Nikonos II Underwater Camera - $50 (St Croix)
$50 - Made by Nikon, this camera is rated for depths up to 160 feet. The body is die cast aluminum alloy sealed with O-ring gaskets. It's a bit dated but it functions perfectly. It's in great shape with only minor scratches.
For pick up on the west end of St Croix
Craigslist ad is here: http://virgin.craigslist.org/pho/5382586336.html