This guy here is a Decorator Crab. It mastered the art of disguise by picking up various life-forms and sticking it on its shell. It can crawl across the reef, but when it holds still it's practically invisible in plain sight. Pretty cool.
This guy was hanging out at Point Lobos State Park in about 40 feet of sea-water in Whaler's Cove. This is my favorite (local) SCUBA spot. You have to make reservations well in advance since they only let in 30 divers per day, but that makes for a very pleasant experience. They have a boat ramp, bathrooms, picnic tables, and gorgeous nature paths to keep you occupied during your surface time. These are also very nice for those who don't do the whole SCUBA thing.
Underwater photography is probably the hardest photography to get right... with the possible exception of astro-photography. It's much easier in the tropics where the visibility is measured in hundreds of feet rather than tens. In Monterey Bay, it's more like a jungle while the tropics are more like a desert. In any case, there's not a whole lot of light available and using a flash tends to just light up all the sediment in the water. In fact, that was the case for this shot. There was a ton of sediment that I had to clean out in Photoshop.