<html><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:14pt"><div style="color: rgb(34, 34, 34); font-family: arial, sans-serif; font-size: 12.800000190734863px;">Just something interesting I found in G.L. with regard to depth</div><div style="color: rgb(34, 34, 34); font-family: arial, sans-serif; font-size: 12.800000190734863px;">rating of acrylic hemispheres.</div><div style="color: rgb(34, 34, 34); font-family: arial, sans-serif; font-size: 12.800000190734863px;">A dome rated for 990 ft (30 bar) in 10C water temperature is only </div><div style="color: rgb(34, 34, 34); font-family: arial, sans-serif; font-size: 12.800000190734863px;">rated to 495 ft (15 bar) in 38C. </div><div style="color: rgb(34, 34, 34); font-family: arial, sans-serif; font-size: 12.800000190734863px;">According to this simple sea temperature at depth
profiler </div><div style="color: rgb(34, 34, 34); font-family: arial, sans-serif; font-size: 12.800000190734863px;"><span style="font-size: 15px; line-height: 19px; white-space: nowrap;"><a href="http://www.windows2universe.org/earth/Water/temp.html" target="_blank" style="color: rgb(17, 85, 204);">http://www.windows2universe.<wbr>org/earth/Water/temp.html</a></span></div><div style="color: rgb(34, 34, 34); font-family: arial, sans-serif; font-size: 12.800000190734863px;"><span style="font-size: 15px; line-height: 19px; white-space: nowrap;">at 600 ft most water is under 10C. So you would never expose the dome to</span></div><div style="color: rgb(34, 34, 34); font-family: arial, sans-serif; font-size: 12.800000190734863px;"><span style="font-size: 15px; line-height: 19px; white-space: nowrap;">overly high pressures at high temperatures.</span></div><div style="color: rgb(34, 34, 34); font-family: arial, sans-serif; font-size:
12.800000190734863px;"><span style="font-size: 15px; line-height: 19px; white-space: nowrap;">I am not sure how G.L. deal with this issue & whether with deeper diving submarines</span></div><div style="color: rgb(34, 34, 34); font-family: arial, sans-serif; font-size: 12.800000190734863px;"><span style="font-size: 15px; line-height: 19px; white-space: nowrap;">you would just claim to operate in low temperatures & go for the largest depth</span></div><div style="color: rgb(34, 34, 34); font-family: arial, sans-serif; font-size: 12.800000190734863px;"><span style="font-size: 15px; line-height: 19px; white-space: nowrap;">rating for that dome.</span></div><div style="color: rgb(34, 34, 34); font-family: arial, sans-serif; font-size: 12.800000190734863px;"><span style="font-size: 15px; line-height: 19px; white-space: nowrap;">To add another dimension to this, I guess you would need to factor in the cabin </span></div><div style="color: rgb(34,
34, 34); font-family: arial, sans-serif; font-size: 12.800000190734863px;"><span style="font-size: 15px; line-height: 19px; white-space: nowrap;">temperature, because that would be effecting the inside of the acrylic.</span></div><div style="color: rgb(34, 34, 34); font-family: arial, sans-serif; font-size: 12.800000190734863px;"><span style="font-size: 15px; line-height: 19px; white-space: nowrap;">Also the acrylic having high thermal insulation properties would be slow to cool</span></div><div style="color: rgb(34, 34, 34); font-family: arial, sans-serif; font-size: 12.800000190734863px;"><span style="font-size: 15px; line-height: 19px; white-space: nowrap;">down & would remain at a higher temperature than the surrounding water for a</span></div><div style="color: rgb(34, 34, 34); font-family: arial, sans-serif; font-size: 12.800000190734863px;"><span style="font-size: 15px; line-height: 19px; white-space: nowrap;">time, especially if diving
quickly.</span></div><div style="color: rgb(34, 34, 34); font-family: arial, sans-serif; font-size: 12.800000190734863px;"><span style="font-size: 15px; line-height: 19px; white-space: nowrap;">On the plus side there is something like a 5x safety factor in there.</span></div><div style="color: rgb(34, 34, 34); font-family: arial, sans-serif; font-size: 12.800000190734863px;"><span style="font-size: 15px; line-height: 19px; white-space: nowrap;">Vance did you ever strike relatively warm temperatures at depth?</span><br></div><div style="color: rgb(34, 34, 34); font-family: arial, sans-serif; font-size: 12.800000190734863px;"><span style="font-size: 15px; line-height: 19px; white-space: nowrap;">Regards Alan</span></div><div><span style="font-size: 15px; line-height: 19px; white-space: nowrap;"><br></span></div></div></body></html>