[PSUBS-MAILIST] onboard gear
MerlinSub@t-online.de via Personal_Submersibles
personal_submersibles at psubs.org
Wed May 1 05:03:04 EDT 2019
Really good training video. Shall safe to the Psubs server..
I have 5 or so devices for the Euronaut. Pretty old USNavy devices form the
80ies and far over it expected lifetime.
But it was nessesary to renew the neck scirt. Was pretty hard. Any small
diver suit maker or reair company can do these job.
We let them make new scirts from Neopren. 50 USD or so each. Replacement
comes without a neck hole
from the suit repair company. We make the holes ourself according to the
smallest crew member neck.
In case you have no LP hose access you can fill the unit with the small
inflatour mouse tube.
This is clear opposite to the instruction video - but better than to lost
your life.
No.6 unit on board has a blue mark on his bag - it is our training device o
teach new crew members.
The other ones are sealed.
I think you can may convert a new divers vest BCD into such a device.80% of
the device is allready on a BCD.
Show the video to a diver suit repair company and give them the new BCD to
convert is may an idear.
The unit with a small air pony bottle as the mmost BCD have - will be a
great update- no need of a LP Hose anymore.
If some of your guys try so for such a conversion - give the comunity here
a call
- may it will be cheaper if you can convet a bunch.
vbr Carsten
-----Original-Nachricht-----
Betreff: Re: [PSUBS-MAILIST] onboard gear
Datum: 2019-04-30T23:09:56+0200
Von: "Cliff Redus via Personal_Submersibles"
<personal_submersibles at psubs.org>
An: "Personal Submersibles General Discussion"
<personal_submersibles at psubs.org>
If you have not had a chance to see this old US Navy training film on
submarine escape, you might want enjoy this.
https://www.youtube.com/watch?v=ffOJEJwWSbs
<https://www.youtube.com/watch?v=ffOJEJwWSbs>
The training is on using the Steinke Hood. I use this appliance on my
boat. Even though it is getting harder to find this hoods, they surface on
Ebay periodically.
Cliff
On Saturday, April 27, 2019, 9:11:53 AM CDT, MerlinSub at t-online.de via
Personal_Submersibles <personal_submersibles at psubs.org> wrote:
Why you want to breath the first minute of your fly?
Just ensure that the gas can get out of our lungs to not overpressure it.
And by the way - if you not breath you can not get additional gas which can
expant into your blood.
And how long you can stop breathing has more to do with your brain - than
with your lungs.
I am now 54 and can stop not more than 1 minute. In my best time and with
training it was easy over 2.
But this is pure theoretical. The best equipment to surfive a submarine
exit is - training.
The lung can overexpant easy but this will happend more or less on the
last 10 meters to the surface.
If you have the training and expierence to slow down your speed there it
will help a lot.
-----Original-Nachricht-----
Betreff: Re: [PSUBS-MAILIST] onboard gear
Datum: 2019-04-27T05:24:20+0200
Von: "Alan via Personal_Submersibles" <personal_submersibles at psubs.org>
An: "Personal Submersibles General Discussion"
<personal_submersibles at psubs.org>
Thanks Tom, a lot to think about.
Yes breathing from the BCD could be problematic on a deep ascent as the
gas would be expanding very little over the first few hundred feet & as you
say you could easily consume it & reduce your flotation.
Alan
On 27/04/2019, at 2:24 PM, TOM WHENT via Personal_Submersibles <
personal_submersibles at psubs.org <mailto:personal_submersibles at psubs.org> >
wrote:
That is a whole lot of task loading for an emergency. Chances are
little of this will be reflexive from repeated practice. Having a good
non narcotic gas to breathe during flood/exit procedures would be
beneficial in keeping your head. Keep in mind that helium on boards
2.7 times faster than nitrogen and also comes out of your tissues that
much faster. Too much time breathing on it might cause you to be
severely bent before reaching the surface on a fast ascent. Most helium
bends occur under water and it will even off gas through your eyes.
I've never experienced this but I have heard that it is painful.
Breathing from a BCD seems like a bad idea to me. It would be
marginally passable as long as you are certain that you are ascending.
Accidentally wasting or venting your buoyancy gas would be disastrous.
Many trained divers struggle with buoyancy control and can't manipulate
inflators with cold hands or in panic.
Coming up fast from any depth, you will need to ensure that you are
exhaling continually, or able to breath in and out so that your airway
is never closed. You have no pain mechanism in your body to alert you
to a lung overpressure. If you rupture a lung you have no chance of
survival even if you do reach the surface.
I had thought about the idea of wearing a neoprene wetsuit inside the
sub as an alternate means of buoyancy and environmental protection but
after considering the depths you guys are escaping from, that too would
have minimal buoyancy due to the crush on the suit from the pressure.
It would however provide some warmth, even if marginally.
Whatever solution you choose, it will have to be simple enough to
deploy under the worst conditions imaginable and preferably protect
your airway on the surface if you should lose consciousness.
I'm generally not an advocate of full face masks for scuba diving, but
in this circumstance, if you had one and a means of flotation, you
would stand a better chance of survival than using a regulator (or BCD
inflator) which will fall out of your mouth if you lose consciousness.
You generally cannot use the firefighter style face mask, but must use
one designed for diving. The reason being that the latter will have a
flexible nose pocket to allow you to pinch it for equalizing.
The hood and escape suits look better all the time.
Tom
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On Fri, Apr 26, 2019 at 8:14 PM -0400, "Alan via Personal_Submersibles"
<personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org> > wrote:
Carsten,
yes you could rely on air out of your BCD but it is not regarded as a
good
practice because of disinfectants used to clean out BCDs. You would
need
to find a suitable sterilising product. But this is an emergency!
I think maybe, as I have said, an escape plan for every 100 ft based
on the
volume of your sub, how quickly you can flood it, how quickly you can
equalise
your ears & what mixed gas you need to avoid getting narced, bent &
O2
Poisoning. Beyond certain depths you would need to start breathing
mixed
gas from a pony bottle or whatever as the hull equalised.
Now you have me thinking!!! What about an external scuba tank full of
mixed
gas plumbed through to the cabin to breath from during the flooding
of the hull,
this would give you a lot more time to equalise your ears! Plumb this
tank to
act as a reserve ballast blow so it is not wasted. Leave the sub with
the pony
bottle full of mixed gas & inflate the horseshoe BCD with it, then
breath from
the BCD.
Alan
On 27/04/2019, at 9:45 AM, MerlinSub at t-online.de
<mailto:MerlinSub at t-online.de> via Personal_Submersibles <
personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org> > wrote:
Alan the pony is just for the first filling the vest in the
moment you leave the sub.
During the fast as possible way to the surface the air in the
vest expand all the
time and leave via the overpressure valve.
Imagine you have a vest of say 4 Liter. How much air will be in
if you leave the sub in 100 meter deeps?
Right - around 40 liters. During your way to the surface 36
liters will leave via the overpressure vale.
Pretty much air to breath. The pony bottle is just there for the
first filling- so you have not to fill tthe
vest wih your lungs because this is exhaust gas and the process
may exhaust you also.
A filled 220 bar by 0,5 Liter pony bottle contains 110 liter
expand gas.
If we assume the vest has 4 Liters volume you can fill the vest
up to a depth equal to 27 bar or 270 meter dephts.
And you can breath all these 110Liter air from the vest except
the last 4 liters which you need on the surface
for bouancy.
In real life it is may better first to leave the sub and than
open the valve to fill the vest.
Otherwise it makes you more bulky and you have the possibility to
scratch the vest somewere on your sub exit.
If you have no expiernce with such vest you should traning it in
a 2-4 meter depth pool to get an feeling for it.
On Euronaut we have all that gear on board. Scuba vest, Steinke
hoods and dive gear including suits.
On a emergency exit of a sunen military argentinna submarnne
which was sunken in the 80ies or 90ies some crew members manage
to escape from 40 meter depth. The guys with the Steinke Hoods
and no dive expierence survifed all.
The colleges with the scuba expierence use the dive gears - help
the other guys to get out -
and died later on decompression thickness. :-(
-----Original-Nachricht-----
Betreff: Re: [PSUBS-MAILIST] onboard gear
Datum: 2019-04-26T23:03:14+0200
Von: "Alan via Personal_Submersibles" <
personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org> >
An: "Personal Submersibles General Discussion" <
personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org> >
Sean / all,
the cold will certainly be a factor but you will be exposed to
that for some
time while the submarine fills with water & equalises. So the
extra 15 seconds
grabbing an external tank won't be major.
What I fear most is bursting my ear drums, & freezing water in
the inner ear.
I imagine this would be very painful, maybe like brain freeze,
but I am only guessing.
Some people have more problems than others equalising & once you
start to
feel pain in your ear from pressure it is more difficult to
equalise.
I think some control on the flooding speed to let you equalise
your ears would
be an asset. Pitty to burst your ear drums when you might be
doing a simple
escape from 100ft.
As Emile & Carsten showed with their practice escapes; they could
get out
relatively easily, & with a bit of air ( 6 cu ft pony bottle )
you could get to the
surface easy enough.
If I were escaping from deeper I would use a pony bottle with
mixed gas some
time after the equivalent of 150ft & this would buy me a bit of
time to equalise
& save my ears, then escape & use my large mixed gas tank to go
to the surface
making stops if I felt able.
There is sense in you saying Keep It Simple, but if you pre plan
& practice, a
more complex but safer escape is possible. Maybe work out how
long it is going
to take to fill your particular sub at varying depths, how
quickly you could equalise
for varying depths. How long your pony bottle would last you &
have a knowledge
of what stops would be best for the varying depths you may escape
from.
At least that would take away a lot of the fear of the unknown &
reduce panic.
BTW I am a diver & amateur speleologist so used to cold wet tight
spaces.
Alan
On 27/04/2019, at 12:17 AM, Sean T. Stevenson via
Personal_Submersibles <personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org> > wrote:
Alan - Don't overthink this. A buoyant emergency ascent can
get you to the surface in less than 60 seconds if you are not
purposefully attempting to limit your ascent rate. How long
can you hold your breath (not that you should)? A gas source
helps you avoid a hypoxic blackout, but with a hood of any
description you shouldn't drown. You'll just end up
rebreathing some of the hood gas. As we discussed earlier,
hypothermia will be an issue, as will the exposure time - it
is actually better to get up from depth ASAP than to spend
time messing around at depth and then having a bunch of stuff
slowing your ascent while deep. My point about the gas
consumption was to illustrate how impractical it would be to
carry sufficient gas to enable an ascent as a diver would do
it.
Sean
-------- Original Message --------
On Apr 25, 2019, 23:39, Alan via Personal_Submersibles <
personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org> > wrote:
More thoughts on escape...
Went in to a couple of dive shops today looking at pony
bottles.
The smallest they were selling were 19 cu ft. I did see a
13 cu ft they were
filling. Both looked too big for my intended dual purpose
use of a horse shoe
BCD as a life jacked. A bit clutsy getting in to the sub
wearing a BCD & large
tank. They make a 6 cu ft pony bottle but I would have to
import it & it would
only get me to the surface from about 100ft.
I had the thought of filling a 6 cu ft pony bottle with
mixed gas & having an
80 cuft mixed gas tank outside the hull. It could have an
octopus regulator
( to avoid free flow) permanently on the 80 & a quick
disconnect fitting on it that
a hose attaches to for use as a reserve ballast blow.
So you breath through your pony reg while flooding &
escaping, then when
outside use the 80 cu ft tank reg while detaching the
ballast hose, attaching
the BCD connection and un latching the tank.
It could be practiced in the garage with your eyes closed
& done in about 15
seconds. Any thoughts on this?
Alan
On 26/04/2019, at 1:38 PM, Alan via Personal_Submersibles
<personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org> > wrote:
Thanks Carsten,
I am thinking I may go with something similar; a
horse collar BCD with a
13 cu ft pony bottle. (BCD below).
It could double as a life jacket, has manual
inflation & push button inflation.
I would have a regulator off the pony bottle as well.
The BCD has an over inflation valve but if you wanted
your air to last in an emergency
you could breath expanding air out of the BCD through
the manual inflation
mouth piece. With a BCD as apposed to a life jacket
you have the chance to
slow your ascent & do a decompression stop.
I am not sure what the maximum depth is that I could
come up from with a 13 cu ft
tank.
I could use this for shallow dives or as a supplement
for snorkelling, so it won't be
sitting in a sub doing nothing.
Alan
<image1.PNG>
On 25/04/2019, at 7:42 PM, MerlinSub at t-online.de
<mailto:MerlinSub at t-online.de> via
Personal_Submersibles <
personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org> > wrote:
We figure out that the best escape equipment will
be a Steinke hood (hard to get now)
or a traditional scuba west with a small on board
air bottle.
Both give you the high lift capacity you need to
make an fast rise.
For bigger subs and cold waters light diving
suits will help muxh.
Second it will help you a lot if you allready a
diver or had make a course.
We make some years ago some exercieces with a
semi finish Psub scuttled in a pool .
First go out were really bad feelings and schock
about the water rush in and the cold and so.Have
these in mind: panic.
But after 3-4 times and with the knowledge it was
fun to do the escape exercice.
With training and the right gear I see no problem
to get out of a sub even from much greater
dephts.
The releasing signal bouy should have a stopper
on the reel. Otherwise a 300 m rope bouy will
drived far away with a sub sunken in 30 m .
And make the life of the rescue diver much
harder. The rope shall resitance the force a
human can pull on it - say 150 Kg at least.
Somebody on the surface can come to the
conclusion to lift the baot on these rope- better
make a mark on the Bouy "Sunken submarine - dont
pull on the rope!"
vbr Carsten
-----Original-Nachricht-----
Betreff: Re: [PSUBS-MAILIST] onboard gear
Datum: 2019-04-25T00:07:11+0200
Von: "Alan via Personal_Submersibles" <
personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org> >
An: "Personal Submersibles General Discussion" <
personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org> >
Perhaps a Psub plan for escape from down to
100ft, as you could do this
100 times out of 100 if you knew what you were
doing.
Also even though most subs are capable of diving
deeper there is more
probability that entanglements like ropes & nets
are going to be encountered
In shallower depths.
BTW the pressure in the sub is going to increase
incrementally quicker as it
floods & you need to keep equalising your ears
like mad toward the end or
you'll burst your ear drums, & aside from that
pain, will have freezing water
going in to your inner ear. That would increase
your chances of failure.
Alan
On 24/04/2019, at 4:12 PM, Stephen Fordyce via
Personal_Submersibles <
personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org> > wrote:
Hi all,
This is an interesting discussion I've been
meaning to weigh in on - as an experienced
tech/deep/cave diver rather than a sub
person.
My feel is that unless the escapee is an
experienced diver (and even then), the
chances of a successful escape from below
50m/150ft depth are so low as to be almost
negligible. And I'd suggest having a plan for
such is (almost) an entirely false sense of
security - and energy should be diverted
elsewhere to reduce risk.
A few of the scarier things like narcosis and
the bends have had a lot of airtime, but
basic stuff like keeping a diving mask clear
(and one that's probably fogging up),
panic-breathing a soggy SCUBA reg and dealing
with the thermal shock of sudden immersion
are likely to cause death by drowning much
earlier. Don't underestimate the thermal
shock and how useless it makes you with no
exposure suit. Breathing a regulator without
a mask is a skill in itself. You're probably
already suffering from fatigue, stress, high
CO2 and/or low O2 from waiting for rescue and
getting to such a desperate point. All of
these cause significant mental impairment
before you even start on the escape.
Forget about planning to hold stops on the
way up, switch gases or do decompression.
Even if you're lucky enough to still be
conscious and thinking in the latter stages
of the rapid ascent, personal buoyancy
control is unlikely to be possible.
So if you're going to attempt to escape, I
suggest the best chance for survival is to
plan on a very simple setup (per person),
buoyancy for a rapid/undignified ascent, and
needing urgent medical attention and oxygen
on the surface. Maybe carry a cylinder of
trimix on board to give yourself a better
chance of being able to think, but it's a big
weight/cost premium if it's enough to be
useful. Use a divers (with closed bottom)
"lift bag" and a loop around at the armpits
as a quick and easy way to get a person
shooting upwards. CO2 inflatable life jacket
to keep unconscious head above water on
surface. (Inflate at depth while conscious -
won't fill much, but will expand on way up)
Might be better put towards things like extra
life support duration. Consider doing
regular practise drills that are as realistic
as possible.
Highly skilled divers mess up basic skills in
stressful situations and die with sad
regularity. Don't imagine your (and
passengers) chances of winging it at depth
will be anything other than tiny. 30m/90ft
and shallower they are a bit better.
I hate to be negative, but perhaps for deep
PSUB diving, the inability to escape is just
one of those residual risks that can be
accepted for a recreational activity.
Cheers,
Steve Fordyce
Melbourne, Australia
On Wed, 24 Apr 2019 10:57 hank pronk via
Personal_Submersibles <
personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org> >
wrote:
I think all submarines should have an
escape pod or jettisoning occupant sphere.
I admit I made a mistake with my escape pod
by making it only for one. An easy fix
that I will likely tackle, and that is to
stretch the pod making it big enough for
two. E3000 has a jettisoning occupant
sphere.
Hank
On Tuesday, April 23, 2019, 5:39:01 PM MDT,
TOM WHENT via Personal_Submersibles <
personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org> >
wrote:
A compact bail out rebreather might be the
most surviveable solution however it would
require a significant commitment in
training, maintenance as well as the cost
of the equipment itself. I personally have
not been following the development of
bailout rebreathers, although i'm aware
that some are working on this. My dive
group relies on planning for open circuit
bailout in the event of rebreather failure.
If money is no object, I am partial to the
ISC Megalodon classic CCR. In terms of
robustness and deep water capability, you
will find none better.
It will get you home and flies itself. It
is an electronic CCR which maintains PPO2
for the user. This is the unit I dive
myself and feel very confident in.
KISS classics, which are a simple and
reliable mechanical CCR apparatus, often
come up on the used market in affordable
price ranges.
Both would require significant equipment
specific training but would get you out of
a 400 ft jam with only two small cylinders
and gas to spare. CCR duration is driven by
metabolic rate and is the same irrespective
of operational depth. Even the lowest end
units will give you an hour plus.
On ascent, rebreathers do require the diver
to be monitoring the oxygen level display
in the breathing loop and very likely
adding oxygen manually - particularly in
the mCCR type on a fast ascent.
The other benefit of this setup is that an
air cell for buoyancy can be integrated
easily in one compact package.
It sounds like a lot of effort for the non
diver, but it is a functional answer to the
risks of a sub disabled in deep water.
What is a life worth?
How much risk can one accept for a hobby?
Food for thought anyhow.
Get Outlook for Android
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On Tue, Apr 23, 2019 at 7:34 PM -0400,
"Alan via Personal_Submersibles" <
personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org> >
wrote:
As an alternative to possible death or even
worse, the loss of your submarine,
I am in early stages of designing a buoy
release mechanism that is used
for surfacing safely but has an emergency
beacon that can be activated
with an electro magnet.
Thoughts are to use 150 lb braid with a
tensioning mechanism & have an
automatic boat latch mechanism that can
slide down the braid but is fixed
to the buoy with instructions, "tie a long
rope to the ring & let down untill
latch attaches to submarine. Pull up"
The automatic latch is a device that Phil
described & provided a drawing for,
but there may be a cheap & suitable
automatic boat latch ( used on release
& retrieve on boat launching) on the
market. I am still searching & if anyone
knows of one that may be suitable I would
be interested.
Alan
On 24/04/2019, at 10:51 AM, Sean T.
Stevenson via Personal_Submersibles <
personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org> >
wrote:
There is a significant difference
between submarine escape and a planned
SCUBA dive with regard to both the dive
profile and the equipment that you can
reasonably carry. An escape is more
akin to what is known as a buoyant
emergency ascent in recreational
diving, where you need to get to the
surface yesterday and all other
considerations are secondary. In this
specific case, trying to keep to a slow
ascent rate would significantly
increase the incurred decompression
obligation that you must necessarily
then blow off as you ascend through the
shallows, introducing an even greater
risk. You also have the hypothermia
issue to deal with if you are not
equipped with exposure protection
specifically intended for submersion at
depth. Being cold reduces decompression
effectiveness. In order to keep to a
target ascent rate or perform
decompression stops, you would need
diving instrumentation (depth gauge and
timer), would need the skills and
experience to perform gas switches and
hold stops, and would need
significantly more bulky equipment to
have enough gas to perform a proper
decompression (slow ascent, gas
switches, etc.).
When I dive to these depths on SCUBA, I
wear twin cylinders (>100 cu. ft. each)
on my back with the bottom gas (10/70
or whatever for the planned depth and
time), plus three or four off-board
cylinders (80s) carrying the
decompression gases (typically 21/35,
35/25, EAN50 and oxygen), plus a small
bottle of argon for drysuit inflation.
Obviously, as an escapee you are not so
equipped. Far better to lockout as
quickly as possible and rapidly ascend
(with buoyant assist) to get clear of
those depths where you are ongassing
the most, and if at all possible, to
slow the ascent as you approach the
surface, and then have your surface
support or emergency responders
administer oxygen as transport is
arranged to recompression. To be
clear, an emergency escape from a
disabled submarine at these depths is
not even remotely a good idea - it is
simply a marginally better idea than
dying on the bottom.
To illustrate, if you were to attempt a
continuous ascent from 300 fsw, the
average depth is 150 fsw, which is
about 5.5 atmospheres absolute. If you
assume a surface air consumption rate
of 1 cu. ft. / minute (high, but
typical of a diver who is stressed or
working hard, which is inevitable in a
submarine escape scenario), that
corresponds to 5.5 cu. ft. / min at the
average depth of the ascent. At a 30
ft/min ascent rate, that's 10 minutes,
or 55 cu. ft. of gas consumed just for
the continuous ascent with no
decompression stops, without
consideration for the gas consumed
while blowing down and locking out.
You can judge for yourself the
practicality of carrying an 80 on a
PSub sized vessel just for emergency
escape purposes.
Sean
‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
On Tuesday, April 23, 2019 12:32 PM,
David Colombo via Personal_Submersibles
<personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org>
> wrote:
Hi Guys, This topic is fascinating
and scary at the same time. Accent
rates form the old Navy logs had
60ft / minute max with a
recommended max accent rate of 30
ft/ min. At 300ft escape depth,
what volume of mixed gases would
you need for a 10 minute accent
assuming you choose not to swim
60ft/min.
Best Regards,
David Colombo
804 College Ave
Santa Rosa, CA. 95404
(707) 536-1424
www.SeaQuestor.com
<http://www.SeaQuestor.com>
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As an alternative to possible death or even
worse, the loss of your submarine,
I am in early stages of designing a buoy
release mechanism that is used
for surfacing safely but has an emergency
beacon that can be activated
with an electro magnet.
Thoughts are to use 150 lb braid with a
tensioning mechanism & have an
automatic boat latch mechanism that can
slide down the braid but is fixed
to the buoy with instructions, "tie a long
rope to the ring & let down untill
latch attaches to submarine. Pull up"
The automatic latch is a device that Phil
described & provided a drawing for,
but there may be a cheap & suitable
automatic boat latch ( used on release
& retrieve on boat launching) on the
market. I am still searching & if anyone
knows of one that may be suitable I would
be interested.
Alan
On 24/04/2019, at 10:51 AM, Sean T.
Stevenson via Personal_Submersibles <
personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org> >
wrote:
There is a significant difference
between submarine escape and a planned
SCUBA dive with regard to both the dive
profile and the equipment that you can
reasonably carry. An escape is more
akin to what is known as a buoyant
emergency ascent in recreational
diving, where you need to get to the
surface yesterday and all other
considerations are secondary. In this
specific case, trying to keep to a slow
ascent rate would significantly
increase the incurred decompression
obligation that you must necessarily
then blow off as you ascend through the
shallows, introducing an even greater
risk. You also have the hypothermia
issue to deal with if you are not
equipped with exposure protection
specifically intended for submersion at
depth. Being cold reduces decompression
effectiveness. In order to keep to a
target ascent rate or perform
decompression stops, you would need
diving instrumentation (depth gauge and
timer), would need the skills and
experience to perform gas switches and
hold stops, and would need
significantly more bulky equipment to
have enough gas to perform a proper
decompression (slow ascent, gas
switches, etc.).
When I dive to these depths on SCUBA, I
wear twin cylinders (>100 cu. ft. each)
on my back with the bottom gas (10/70
or whatever for the planned depth and
time), plus three or four off-board
cylinders (80s) carrying the
decompression gases (typically 21/35,
35/25, EAN50 and oxygen), plus a small
bottle of argon for drysuit inflation.
Obviously, as an escapee you are not so
equipped. Far better to lockout as
quickly as possible and rapidly ascend
(with buoyant assist) to get clear of
those depths where you are ongassing
the most, and if at all possible, to
slow the ascent as you approach the
surface, and then have your surface
support or emergency responders
administer oxygen as transport is
arranged to recompression. To be
clear, an emergency escape from a
disabled submarine at these depths is
not even remotely a good idea - it is
simply a marginally better idea than
dying on the bottom.
To illustrate, if you were to attempt a
continuous ascent from 300 fsw, the
average depth is 150 fsw, which is
about 5.5 atmospheres absolute. If you
assume a surface air consumption rate
of 1 cu. ft. / minute (high, but
typical of a diver who is stressed or
working hard, which is inevitable in a
submarine escape scenario), that
corresponds to 5.5 cu. ft. / min at the
average depth of the ascent. At a 30
ft/min ascent rate, that's 10 minutes,
or 55 cu. ft. of gas consumed just for
the continuous ascent with no
decompression stops, without
consideration for the gas consumed
while blowing down and locking out.
You can judge for yourself the
practicality of carrying an 80 on a
PSub sized vessel just for emergency
escape purposes.
Sean
‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
On Tuesday, April 23, 2019 12:32 PM,
David Colombo via Personal_Submersibles
<personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org>
> wrote:
Hi Guys, This topic is fascinating
and scary at the same time. Accent
rates form the old Navy logs had
60ft / minute max with a
recommended max accent rate of 30
ft/ min. At 300ft escape depth,
what volume of mixed gases would
you need for a 10 minute accent
assuming you choose not to swim
60ft/min.
Best Regards,
David Colombo
804 College Ave
Santa Rosa, CA. 95404
(707) 536-1424
www.SeaQuestor.com
<http://www.SeaQuestor.com>
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Carsten,
yes you could rely on air out of your BCD but it is not regarded as a
good
practice because of disinfectants used to clean out BCDs. You would
need
to find a suitable sterilising product. But this is an emergency!
I think maybe, as I have said, an escape plan for every 100 ft based on
the
volume of your sub, how quickly you can flood it, how quickly you can
equalise
your ears & what mixed gas you need to avoid getting narced, bent & O2
Poisoning. Beyond certain depths you would need to start breathing
mixed
gas from a pony bottle or whatever as the hull equalised.
Now you have me thinking!!! What about an external scuba tank full of
mixed
gas plumbed through to the cabin to breath from during the flooding of
the hull,
this would give you a lot more time to equalise your ears! Plumb this
tank to
act as a reserve ballast blow so it is not wasted. Leave the sub with
the pony
bottle full of mixed gas & inflate the horseshoe BCD with it, then
breath from
the BCD.
Alan
On 27/04/2019, at 9:45 AM, MerlinSub at t-online.de
<mailto:MerlinSub at t-online.de> via Personal_Submersibles <
personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org> > wrote:
Alan the pony is just for the first filling the vest in the moment
you leave the sub.
During the fast as possible way to the surface the air in the vest
expand all the
time and leave via the overpressure valve.
Imagine you have a vest of say 4 Liter. How much air will be in if
you leave the sub in 100 meter deeps?
Right - around 40 liters. During your way to the surface 36 liters
will leave via the overpressure vale.
Pretty much air to breath. The pony bottle is just there for the
first filling- so you have not to fill tthe
vest wih your lungs because this is exhaust gas and the process may
exhaust you also.
A filled 220 bar by 0,5 Liter pony bottle contains 110 liter
expand gas.
If we assume the vest has 4 Liters volume you can fill the vest up
to a depth equal to 27 bar or 270 meter dephts.
And you can breath all these 110Liter air from the vest except the
last 4 liters which you need on the surface
for bouancy.
In real life it is may better first to leave the sub and than open
the valve to fill the vest.
Otherwise it makes you more bulky and you have the possibility to
scratch the vest somewere on your sub exit.
If you have no expiernce with such vest you should traning it in a
2-4 meter depth pool to get an feeling for it.
On Euronaut we have all that gear on board. Scuba vest, Steinke
hoods and dive gear including suits.
On a emergency exit of a sunen military argentinna submarnne which
was sunken in the 80ies or 90ies some crew members manage to escape
from 40 meter depth. The guys with the Steinke Hoods and no dive
expierence survifed all.
The colleges with the scuba expierence use the dive gears - help
the other guys to get out -
and died later on decompression thickness. :-(
-----Original-Nachricht-----
Betreff: Re: [PSUBS-MAILIST] onboard gear
Datum: 2019-04-26T23:03:14+0200
Von: "Alan via Personal_Submersibles" <
personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org> >
An: "Personal Submersibles General Discussion" <
personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org> >
Sean / all,
the cold will certainly be a factor but you will be exposed to that
for some
time while the submarine fills with water & equalises. So the extra
15 seconds
grabbing an external tank won't be major.
What I fear most is bursting my ear drums, & freezing water in the
inner ear.
I imagine this would be very painful, maybe like brain freeze, but
I am only guessing.
Some people have more problems than others equalising & once you
start to
feel pain in your ear from pressure it is more difficult to
equalise.
I think some control on the flooding speed to let you equalise your
ears would
be an asset. Pitty to burst your ear drums when you might be doing
a simple
escape from 100ft.
As Emile & Carsten showed with their practice escapes; they could
get out
relatively easily, & with a bit of air ( 6 cu ft pony bottle ) you
could get to the
surface easy enough.
If I were escaping from deeper I would use a pony bottle with mixed
gas some
time after the equivalent of 150ft & this would buy me a bit of
time to equalise
& save my ears, then escape & use my large mixed gas tank to go to
the surface
making stops if I felt able.
There is sense in you saying Keep It Simple, but if you pre plan &
practice, a
more complex but safer escape is possible. Maybe work out how long
it is going
to take to fill your particular sub at varying depths, how quickly
you could equalise
for varying depths. How long your pony bottle would last you & have
a knowledge
of what stops would be best for the varying depths you may escape
from.
At least that would take away a lot of the fear of the unknown &
reduce panic.
BTW I am a diver & amateur speleologist so used to cold wet tight
spaces.
Alan
On 27/04/2019, at 12:17 AM, Sean T. Stevenson via
Personal_Submersibles <personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org> > wrote:
Alan - Don't overthink this. A buoyant emergency ascent can get
you to the surface in less than 60 seconds if you are not
purposefully attempting to limit your ascent rate. How long can
you hold your breath (not that you should)? A gas source helps
you avoid a hypoxic blackout, but with a hood of any
description you shouldn't drown. You'll just end up rebreathing
some of the hood gas. As we discussed earlier, hypothermia will
be an issue, as will the exposure time - it is actually better
to get up from depth ASAP than to spend time messing around at
depth and then having a bunch of stuff slowing your ascent
while deep. My point about the gas consumption was to
illustrate how impractical it would be to carry sufficient gas
to enable an ascent as a diver would do it.
Sean
-------- Original Message --------
On Apr 25, 2019, 23:39, Alan via Personal_Submersibles <
personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org> > wrote:
More thoughts on escape...
Went in to a couple of dive shops today looking at pony
bottles.
The smallest they were selling were 19 cu ft. I did see a
13 cu ft they were
filling. Both looked too big for my intended dual purpose
use of a horse shoe
BCD as a life jacked. A bit clutsy getting in to the sub
wearing a BCD & large
tank. They make a 6 cu ft pony bottle but I would have to
import it & it would
only get me to the surface from about 100ft.
I had the thought of filling a 6 cu ft pony bottle with
mixed gas & having an
80 cuft mixed gas tank outside the hull. It could have an
octopus regulator
( to avoid free flow) permanently on the 80 & a quick
disconnect fitting on it that
a hose attaches to for use as a reserve ballast blow.
So you breath through your pony reg while flooding &
escaping, then when
outside use the 80 cu ft tank reg while detaching the
ballast hose, attaching
the BCD connection and un latching the tank.
It could be practiced in the garage with your eyes closed &
done in about 15
seconds. Any thoughts on this?
Alan
On 26/04/2019, at 1:38 PM, Alan via Personal_Submersibles <
personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org> > wrote:
Thanks Carsten,
I am thinking I may go with something similar; a horse
collar BCD with a
13 cu ft pony bottle. (BCD below).
It could double as a life jacket, has manual inflation
& push button inflation.
I would have a regulator off the pony bottle as well.
The BCD has an over inflation valve but if you wanted
your air to last in an emergency
you could breath expanding air out of the BCD through
the manual inflation
mouth piece. With a BCD as apposed to a life jacket you
have the chance to
slow your ascent & do a decompression stop.
I am not sure what the maximum depth is that I could
come up from with a 13 cu ft
tank.
I could use this for shallow dives or as a supplement
for snorkelling, so it won't be
sitting in a sub doing nothing.
Alan
<image1.PNG>
On 25/04/2019, at 7:42 PM, MerlinSub at t-online.de
<mailto:MerlinSub at t-online.de> via
Personal_Submersibles <personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org> > wrote:
We figure out that the best escape equipment will
be a Steinke hood (hard to get now)
or a traditional scuba west with a small on board
air bottle.
Both give you the high lift capacity you need to
make an fast rise.
For bigger subs and cold waters light diving suits
will help muxh.
Second it will help you a lot if you allready a
diver or had make a course.
We make some years ago some exercieces with a semi
finish Psub scuttled in a pool .
First go out were really bad feelings and schock
about the water rush in and the cold and so.Have
these in mind: panic.
But after 3-4 times and with the knowledge it was
fun to do the escape exercice.
With training and the right gear I see no problem
to get out of a sub even from much greater dephts.
The releasing signal bouy should have a stopper on
the reel. Otherwise a 300 m rope bouy will drived
far away with a sub sunken in 30 m .
And make the life of the rescue diver much harder.
The rope shall resitance the force a human can pull
on it - say 150 Kg at least.
Somebody on the surface can come to the conclusion
to lift the baot on these rope- better make a mark
on the Bouy "Sunken submarine - dont pull on the
rope!"
vbr Carsten
-----Original-Nachricht-----
Betreff: Re: [PSUBS-MAILIST] onboard gear
Datum: 2019-04-25T00:07:11+0200
Von: "Alan via Personal_Submersibles" <
personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org> >
An: "Personal Submersibles General Discussion" <
personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org> >
Perhaps a Psub plan for escape from down to 100ft,
as you could do this
100 times out of 100 if you knew what you were
doing.
Also even though most subs are capable of diving
deeper there is more
probability that entanglements like ropes & nets
are going to be encountered
In shallower depths.
BTW the pressure in the sub is going to increase
incrementally quicker as it
floods & you need to keep equalising your ears like
mad toward the end or
you'll burst your ear drums, & aside from that
pain, will have freezing water
going in to your inner ear. That would increase
your chances of failure.
Alan
On 24/04/2019, at 4:12 PM, Stephen Fordyce via
Personal_Submersibles <
personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org> > wrote:
Hi all,
This is an interesting discussion I've been
meaning to weigh in on - as an experienced
tech/deep/cave diver rather than a sub person.
My feel is that unless the escapee is an
experienced diver (and even then), the chances
of a successful escape from below 50m/150ft
depth are so low as to be almost negligible.
And I'd suggest having a plan for such is
(almost) an entirely false sense of security -
and energy should be diverted elsewhere to
reduce risk.
A few of the scarier things like narcosis and
the bends have had a lot of airtime, but basic
stuff like keeping a diving mask clear (and one
that's probably fogging up), panic-breathing a
soggy SCUBA reg and dealing with the thermal
shock of sudden immersion are likely to cause
death by drowning much earlier. Don't
underestimate the thermal shock and how useless
it makes you with no exposure suit. Breathing a
regulator without a mask is a skill in itself.
You're probably already suffering from fatigue,
stress, high CO2 and/or low O2 from waiting for
rescue and getting to such a desperate point.
All of these cause significant mental
impairment before you even start on the escape.
Forget about planning to hold stops on the way
up, switch gases or do decompression. Even if
you're lucky enough to still be conscious and
thinking in the latter stages of the rapid
ascent, personal buoyancy control is unlikely
to be possible.
So if you're going to attempt to escape, I
suggest the best chance for survival is to plan
on a very simple setup (per person), buoyancy
for a rapid/undignified ascent, and needing
urgent medical attention and oxygen on the
surface. Maybe carry a cylinder of trimix on
board to give yourself a better chance of being
able to think, but it's a big weight/cost
premium if it's enough to be useful. Use a
divers (with closed bottom) "lift bag" and a
loop around at the armpits as a quick and easy
way to get a person shooting upwards. CO2
inflatable life jacket to keep unconscious head
above water on surface. (Inflate at depth while
conscious - won't fill much, but will expand on
way up) Might be better put towards things like
extra life support duration. Consider doing
regular practise drills that are as realistic
as possible.
Highly skilled divers mess up basic skills in
stressful situations and die with sad
regularity. Don't imagine your (and passengers)
chances of winging it at depth will be anything
other than tiny. 30m/90ft and shallower they
are a bit better.
I hate to be negative, but perhaps for deep
PSUB diving, the inability to escape is just
one of those residual risks that can be
accepted for a recreational activity.
Cheers,
Steve Fordyce
Melbourne, Australia
On Wed, 24 Apr 2019 10:57 hank pronk via
Personal_Submersibles <
personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org> >
wrote:
I think all submarines should have an escape
pod or jettisoning occupant sphere. I admit
I made a mistake with my escape pod by making
it only for one. An easy fix that I will
likely tackle, and that is to stretch the pod
making it big enough for two. E3000 has a
jettisoning occupant sphere.
Hank
On Tuesday, April 23, 2019, 5:39:01 PM MDT,
TOM WHENT via Personal_Submersibles <
personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org> >
wrote:
A compact bail out rebreather might be the
most surviveable solution however it would
require a significant commitment in training,
maintenance as well as the cost of the
equipment itself. I personally have not been
following the development of bailout
rebreathers, although i'm aware that some are
working on this. My dive group relies on
planning for open circuit bailout in the
event of rebreather failure.
If money is no object, I am partial to the
ISC Megalodon classic CCR. In terms of
robustness and deep water capability, you
will find none better.
It will get you home and flies itself. It is
an electronic CCR which maintains PPO2 for
the user. This is the unit I dive myself and
feel very confident in.
KISS classics, which are a simple and
reliable mechanical CCR apparatus, often come
up on the used market in affordable price
ranges.
Both would require significant equipment
specific training but would get you out of a
400 ft jam with only two small cylinders and
gas to spare. CCR duration is driven by
metabolic rate and is the same irrespective
of operational depth. Even the lowest end
units will give you an hour plus.
On ascent, rebreathers do require the diver
to be monitoring the oxygen level display in
the breathing loop and very likely adding
oxygen manually - particularly in the mCCR
type on a fast ascent.
The other benefit of this setup is that an
air cell for buoyancy can be integrated
easily in one compact package.
It sounds like a lot of effort for the non
diver, but it is a functional answer to the
risks of a sub disabled in deep water.
What is a life worth?
How much risk can one accept for a hobby?
Food for thought anyhow.
Get Outlook for Android
<https://aka.ms/ghei36>
On Tue, Apr 23, 2019 at 7:34 PM -0400, "Alan
via Personal_Submersibles" <
personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org> >
wrote:
As an alternative to possible death or even
worse, the loss of your submarine,
I am in early stages of designing a buoy
release mechanism that is used
for surfacing safely but has an emergency
beacon that can be activated
with an electro magnet.
Thoughts are to use 150 lb braid with a
tensioning mechanism & have an
automatic boat latch mechanism that can slide
down the braid but is fixed
to the buoy with instructions, "tie a long
rope to the ring & let down untill
latch attaches to submarine. Pull up"
The automatic latch is a device that Phil
described & provided a drawing for,
but there may be a cheap & suitable automatic
boat latch ( used on release
& retrieve on boat launching) on the market.
I am still searching & if anyone
knows of one that may be suitable I would be
interested.
Alan
On 24/04/2019, at 10:51 AM, Sean T. Stevenson
via Personal_Submersibles <
personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org> >
wrote:
There is a significant difference between
submarine escape and a planned SCUBA dive
with regard to both the dive profile and
the equipment that you can reasonably
carry. An escape is more akin to what is
known as a buoyant emergency ascent in
recreational diving, where you need to
get to the surface yesterday and all
other considerations are secondary. In
this specific case, trying to keep to a
slow ascent rate would significantly
increase the incurred decompression
obligation that you must necessarily then
blow off as you ascend through the
shallows, introducing an even greater
risk. You also have the hypothermia
issue to deal with if you are not
equipped with exposure protection
specifically intended for submersion at
depth. Being cold reduces decompression
effectiveness. In order to keep to a
target ascent rate or perform
decompression stops, you would need
diving instrumentation (depth gauge and
timer), would need the skills and
experience to perform gas switches and
hold stops, and would need significantly
more bulky equipment to have enough gas
to perform a proper decompression (slow
ascent, gas switches, etc.).
When I dive to these depths on SCUBA, I
wear twin cylinders (>100 cu. ft. each)
on my back with the bottom gas (10/70 or
whatever for the planned depth and time),
plus three or four off-board cylinders
(80s) carrying the decompression gases
(typically 21/35, 35/25, EAN50 and
oxygen), plus a small bottle of argon for
drysuit inflation. Obviously, as an
escapee you are not so equipped. Far
better to lockout as quickly as possible
and rapidly ascend (with buoyant assist)
to get clear of those depths where you
are ongassing the most, and if at all
possible, to slow the ascent as you
approach the surface, and then have your
surface support or emergency responders
administer oxygen as transport is
arranged to recompression. To be clear,
an emergency escape from a disabled
submarine at these depths is not even
remotely a good idea - it is simply a
marginally better idea than dying on the
bottom.
To illustrate, if you were to attempt a
continuous ascent from 300 fsw, the
average depth is 150 fsw, which is about
5.5 atmospheres absolute. If you assume
a surface air consumption rate of 1 cu.
ft. / minute (high, but typical of a
diver who is stressed or working hard,
which is inevitable in a submarine escape
scenario), that corresponds to 5.5 cu.
ft. / min at the average depth of the
ascent. At a 30 ft/min ascent rate,
that's 10 minutes, or 55 cu. ft. of gas
consumed just for the continuous ascent
with no decompression stops, without
consideration for the gas consumed while
blowing down and locking out. You can
judge for yourself the practicality of
carrying an 80 on a PSub sized vessel
just for emergency escape purposes.
Sean
‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
On Tuesday, April 23, 2019 12:32 PM,
David Colombo via Personal_Submersibles <
personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org>
> wrote:
Hi Guys, This topic is fascinating
and scary at the same time. Accent
rates form the old Navy logs had 60ft
/ minute max with a recommended max
accent rate of 30 ft/ min. At 300ft
escape depth, what volume of mixed
gases would you need for a 10 minute
accent assuming you choose not to
swim 60ft/min.
Best Regards,
David Colombo
804 College Ave
Santa Rosa, CA. 95404
(707) 536-1424
www.SeaQuestor.com
<http://www.SeaQuestor.com>
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<http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles>
As an alternative to possible death or even
worse, the loss of your submarine,
I am in early stages of designing a buoy
release mechanism that is used
for surfacing safely but has an emergency
beacon that can be activated
with an electro magnet.
Thoughts are to use 150 lb braid with a
tensioning mechanism & have an
automatic boat latch mechanism that can slide
down the braid but is fixed
to the buoy with instructions, "tie a long
rope to the ring & let down untill
latch attaches to submarine. Pull up"
The automatic latch is a device that Phil
described & provided a drawing for,
but there may be a cheap & suitable automatic
boat latch ( used on release
& retrieve on boat launching) on the market.
I am still searching & if anyone
knows of one that may be suitable I would be
interested.
Alan
On 24/04/2019, at 10:51 AM, Sean T. Stevenson
via Personal_Submersibles <
personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org> >
wrote:
There is a significant difference between
submarine escape and a planned SCUBA dive
with regard to both the dive profile and
the equipment that you can reasonably
carry. An escape is more akin to what is
known as a buoyant emergency ascent in
recreational diving, where you need to
get to the surface yesterday and all
other considerations are secondary. In
this specific case, trying to keep to a
slow ascent rate would significantly
increase the incurred decompression
obligation that you must necessarily then
blow off as you ascend through the
shallows, introducing an even greater
risk. You also have the hypothermia
issue to deal with if you are not
equipped with exposure protection
specifically intended for submersion at
depth. Being cold reduces decompression
effectiveness. In order to keep to a
target ascent rate or perform
decompression stops, you would need
diving instrumentation (depth gauge and
timer), would need the skills and
experience to perform gas switches and
hold stops, and would need significantly
more bulky equipment to have enough gas
to perform a proper decompression (slow
ascent, gas switches, etc.).
When I dive to these depths on SCUBA, I
wear twin cylinders (>100 cu. ft. each)
on my back with the bottom gas (10/70 or
whatever for the planned depth and time),
plus three or four off-board cylinders
(80s) carrying the decompression gases
(typically 21/35, 35/25, EAN50 and
oxygen), plus a small bottle of argon for
drysuit inflation. Obviously, as an
escapee you are not so equipped. Far
better to lockout as quickly as possible
and rapidly ascend (with buoyant assist)
to get clear of those depths where you
are ongassing the most, and if at all
possible, to slow the ascent as you
approach the surface, and then have your
surface support or emergency responders
administer oxygen as transport is
arranged to recompression. To be clear,
an emergency escape from a disabled
submarine at these depths is not even
remotely a good idea - it is simply a
marginally better idea than dying on the
bottom.
To illustrate, if you were to attempt a
continuous ascent from 300 fsw, the
average depth is 150 fsw, which is about
5.5 atmospheres absolute. If you assume
a surface air consumption rate of 1 cu.
ft. / minute (high, but typical of a
diver who is stressed or working hard,
which is inevitable in a submarine escape
scenario), that corresponds to 5.5 cu.
ft. / min at the average depth of the
ascent. At a 30 ft/min ascent rate,
that's 10 minutes, or 55 cu. ft. of gas
consumed just for the continuous ascent
with no decompression stops, without
consideration for the gas consumed while
blowing down and locking out. You can
judge for yourself the practicality of
carrying an 80 on a PSub sized vessel
just for emergency escape purposes.
Sean
‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
On Tuesday, April 23, 2019 12:32 PM,
David Colombo via Personal_Submersibles <
personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org>
> wrote:
Hi Guys, This topic is fascinating
and scary at the same time. Accent
rates form the old Navy logs had 60ft
/ minute max with a recommended max
accent rate of 30 ft/ min. At 300ft
escape depth, what volume of mixed
gases would you need for a 10 minute
accent assuming you choose not to
swim 60ft/min.
Best Regards,
David Colombo
804 College Ave
Santa Rosa, CA. 95404
(707) 536-1424
www.SeaQuestor.com
<http://www.SeaQuestor.com>
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