My concept...

[unixslave]

Success on the first compiling of the custom navigation software.

I have chosen an ATT Captivate android phone for the processor and control mechanism.

Tests are getting well underway.

For those who think BlueTooth (bt) doesnt work well underwater....

Pssst... guess what... it does. Currently I have about 75 feet of ping/pong messages
working underwater.....

[sthone]

Interesting....is that at 75' of depth or 75' away (in distance) just under the water?

-Steve

[Never prototype]

With all the incredible ideas and tech your working on it would be a shame to limit yourself to working in fresh water. Salt water stops rf cold. You could try magnetic induction communications like divers use for comms between eachother. Great stuff your working on I envy your electrical engineering and programming skills.