<html><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Hey guys - don't get too carried away by re-inventing the wheel - have a look at what you can get off shelf and modify. A number of years ago we used Kodak plastic concertina chemical bottles for compensators - image shows a couple enclosed but exposed to pressure to compensate RPV thrusters - they worked down to 2000-ft depth. We also used plastic Coca Cola containers for for RPV adjustable buoyancy systems - they worked also. As did wine cask bladders! <div>Go to K-Mart - perhaps with some lateral thinking the answer may be sitting on a shelf - I doubt you are trying to achieve James Cameron's depths.</div><div>Cheers</div><div>Keith Gordon</div><div><br></div><div></div></body></html>