One of my friends here at work (now with BP) had a long career with Perry designing ROV's. From time to time, I check Ebay, and we found one for sale there not too long ago. It was one of the old Honeywell "MNV" or "mine neutralization vehicles"
It's starting bid was $10,000 and no one bid on it. Unfortunately, it was one of a few systems that run on 400hz AC power, which is not easy to make. You can't exactly get a 400hz generator from Agrekko.
Here are some shots from the NOAA ship Nancy Foster - I got to go aboard when they were doing deepwater surveys around the Flower Garden Banks:
http://www.reefpix.org/gallery/album31

The Phantom S2 is a small survey ROV (what some people call a "flying eyeball" with video and still cameras. The pilot is controlling it on the left, and the sanctuary manager can see the video feed on his monitor on the left and control the camera using the computer on his right:

Of course, the ROV's used in the projects Alex is working with are MUCH bigger (like the size of a van) and stronger.
Cheers
James