Live in Cayman - dive [SCUBA] a lot and thought about building an ROV for some time. Looks like a fun site - will let you know how it all goes (probably not well with my technical abilities). We have a 6,000 ft. wall here - won't be going that far - went 2,000 ft. wth a commercial unit some time back - very cool!
Anyway - lots of good info here - will be back
Later all ...
Andy B