Snowball, I've used a C750uz on two trips now. The first trip I just fired away and didn't try anything fancy. The results were marginal at best. Lots of blue pictures, with a few good ones within flash range. The second trip, I played with the white balance and had dramatically different results. I was thrilled with my pictures. I had great results at any depth with no flash or strobe. I just reset the WB every time I changed depth of 10 ft or so. I used white sand to do it. Now another diver also had an Olympus, different model that didn't have the large diameter lense and therefore didn't take in as much light. He had to use the flash even with the WB to get anything to turn out. I think some models deal with the WB and light better than others. If the 770 will do that, it's a great underwater camera, if it doesn't chose another. I also took some MOV's with it that added another dimension to my slide show. It breaks up the fishafterfishafterfishafterfish with some motion for the viewers. Good luck.
Nevada
OH, there was a couple of times I did use the zoom. I had to really concentrate on keeping the camera still, a couple of times holding onto coral with my elbows (with a dive skin to not hurt the coral) to stay still. Good results also.