<html><head></head><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:12px"><div id="yui_3_16_0_1_1447248265971_2399" dir="ltr">I was thinking about using CNG (compressed natural gas) tanks for buoyancy. The type 4 tanks are carbon fibre and rated for 3,600 psi and very light. My idea was to keep the tanks full of compressed air so they can withstand the sub depth rating plus a safety margin. I am liking trawl floats may be better now because they are rated high enough and not air filled. The CNG tanks are much cheaper and conveniently shaped. Hmmm not sure now.??</div><div id="yui_3_16_0_1_1447248265971_2399" dir="ltr">Any thoughts or concerns anyone????</div><div id="yui_3_16_0_1_1447248265971_2399" dir="ltr">Hank</div></div></body></html>