[PSUBS-MAILIST] Knotstick

[Alan James via Personal_Submersibles]

I posted this on the 7th but didn't see it.Apologies if you already received it.Anyone looked at or used these.They record speed.http://www.knotstick.com/
They look like they could be mounted by a side view portto show speed. I had to google images of them to see how they wereconstructed. It's a disk on a string that drags through the water. It is attached to a stainless spring in a cylinder & as the spring is extended it pushes a white sleevealong a calibration marked on the cylinder to indicate speed.Alan
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