Was watching an episode of "SciGirls" on PBS with my wife and daughter today and it was rather amazing. A group of four young girls got to work with a couple women at the US Naval Academy and experience underwater ROVs in the form of a small kit called the Sea Perch. I had assumed that the kit was part of the Naval Academy science programs, but then when they showed the kit in a box and explained it came with everything necessary for the program, I had to google it of course.
I was actually impressed with what I found. A full Sea Perch kit is $143 and comes with everything needed to make an underwater ROV. Of course, it is just screaming out for a Basic Stamp or a Propeller to add some additional features (data logging, orientation data, etc). Some of the build techniques in the 33 page PDF are new to me and seem to be rather clever. Sealing the motors in a film canister with toilet ring wax was one item that I was surprised to see, but it appears to work rather well. Really wish I had a pool.........
Here are some links to more details:
Sea Perch website:
SciGirls PBS Show Website for Episode Videos
(Site is heavy on flash, so a little slow in my opinon, but look for the episode titles "Aquabots" that is 27 minutes long. They start working with the ROVs at 6 minutes in, but I recommend watching the whole episode)