I agree that the Canon S Series are excellent cameras. I still use my S90.
I also use Sealife's DC1200 and just purchased a DC1400 off eBay. These too are excellent camras for the novice dive photographer. The Canon does act better (more internal pre-programed settings) as a land camera than the Sealife, but for taking just plain pics both will do fine.
If I am not using an external flash, which is a good idea, I want a UW camera that has an easily settable White Balance; and again both of these cameras, the SeaLife and the Canon S Series do that. The HD Video is a nice feature.
IMO the SeaLife DC1400 is easier to use and is designed for the novice UW dive photoghaper. The Seal does not shot in RAW format for future editing if that is your thing. I have seen free Google Picture edting sofeware do nicely with Sealife pictures, but only minor quality adjustments.
The Canon S-Series is a great all-a-round camera, with a little practice can be just as simple, but is more versitle on land. It does allow RAW shooting and thus more room for afterwater adjustments.
If I had to pick just one for my very
first UW camera I would pick a SeaLife DC1400 with a strope.