Jeff:
I would stay away from the VHS or even S-VHS camcorders for u/w use. It's going to be too big and too close to being obsolete. If you want to go VHS or S-VHS you can probably find used cameras and Ikelite housings on Ebay. I know what your thinking. "You must be crazy to buy something like that on Ebay". However, you would be surprised to see how many people buy these systems use them three times, then put them in the closet for 3 years. I've seen some steals out there. You need to be careful though. I bought an Ikelite housing for my Nikon N90S still camera on Ebay for half of the new cost. I sent it into Ikelite and for $80 they overhauled all the seals and controls and pressure tested it to 250 fsw.
If you definitely want to go "new", and don't want to spend lots of $, go Hi-8 rather than VHS or S-VHS. The reason is that the rig will be much smaller and easier to handle and transport. Also, if you want to go digital later, you can get a DV-8 camera that will playback Hi-8 tapes and transcode them to DV data streams. This is the route I used. I had a Sony TRV-65 (Hi-8) and Ikelite housing for several years and accumulated about 40 hours of select footage from all over Florida and the Carribean. I wanted to do digital editing on the PC, so I bought a Sony TRV-320 DV-8 camera. This allowed me to take my old Hi-8 content and transcode it to a DV stream into my computer using iLink (firewire.) I edit using MediaStudio Pro on the PC and export the final content to archive on DV-8 tapes. Using this technique there is zero quality loss during the editing and archiving process.
I only use the TRV-320 for transcoding and archiving right now. I still shoot all my original source in Hi-8. The reason is that I can get 2 hours of content recorded on one tape, not the limited 60 minutes on DV-8 or mini-DV. I don't like to open the housing on the boat to change tapes and expose the system to salt air. Also, on single CCD cameras, it's nearly impossible to tell the difference between source shot in Hi-8 or DV. You can tell the difference on 3-CCD DV cameras, but they are going to start at 3x the price.
As far as where to buy a system, go through B&H Photo out of New York. You will save about 30% from list price. All the pros shop through B&H. My TRV-320 was selling at Best Buy for $799 when I bought it from B&H for $629.
http://www.bhphotovideo.com
Another piece of advice is to make sure you buy a housing that incorporates a color correcting filter on the OUTSIDE of the housing. Ikelite systems have this. Other's like Ocean Images do not. This is a huge drawback. You need to be able to remove the filter underwater when you go into low-light environments and use artificial lights (like wreck penetrations or swim-throughs.) Otherwise, your content will be tinted RED.
Hope this helps.
Regards,
Brian