Someone just shared this awesome link with me (Thanks Mike) it's live feed from the E/V Nautilus, Dr. Robert Ballards personal ship it is often a live feed from the ROV Hercules a 20hp electro hydraulic Rov rated to 4000m
http://www.nautiluslive.org/
It's funny when I checked it out this morning they just happened to be talking about how you can build your own Rov's.
-Steve
