I'm mostly interested in RC Air, but this in particular intrests me. It's sort of a conflict between you and nature and failure means you lose your investment.

I like to draw and design things to address a particular problem. I was thinking it would be cool to have a sub that isn't so much radio controlled, but instead dives to the bottom of whatever body of water you put it in. When it touches bottom it releases a trip and dumps part of its ballast, just enough to make it rise slowly. Instruments on board will have recorded the maximum depth (pressure) and the excitement will be to obtain a map of a lake with depth indicated, and to release your vehicle in gradually deeper parts to see if it can take the stress. If it comes back to the top, Success! If after a min or two bubbles rise to the surface.. you should have built it better.

I drew these things as my first idea of how to make it release when it touches bottom. Also I was thinking of a way to recover it even if it does collapse. For example a small battery holds a float to the body of the vehicle with an electro magnet either directly or by some sort of relay. The vehicle goes too deep and implodes, floods and stays on the bottom. After time, the battery runs down and releases the float which is attached to a spool of strong thread, like 20 pound test woven fishing line. The float rises, unspooling the thread and you just drive your boat over to the float and haul whats left of your vehicle up.

Any thoughts?

[link=http://i5.photobucket.com/albums/y177/dustyatticx/Vehicle.jpg]Capsule[/link]
[link=http://i5.photobucket.com/albums/y177/dustyatticx/Ballastdump.jpg]Dump[/link]