It's not an SLR, but will give you higher quality images than entry-level SLRs with cheap glass on them--
Canon G-10.
Less than half the price of SLRs with lenses.
You won't have to carry a heavy assortment of lenses.
Very compact. Fits in a small
Otter Box.
130' UW housing is under $200.
Shoots RAW. (Huge benefit with harsh shadows, bright glare, etc...)
Only downside is slow frame rate (1.3 fps). Not good enough if you want to shoot action sequences. If this is the case--simply pick the Nikon or Canon that has the highest FPS and is within your budget. You really can't go wrong with Canon or Nikon SLRs.
Whatever you decide--B&H has unbeatable service and prices. If you find a better price, unless it's Adorama or shipped directly from Amazon, it's likely a used or gray market scam.