I'm the person who started this thread by asking if the Kodak or Fuji cameras are better.
Just to show you what I've been able to do with these cheap plastic wonders, here are some pictures that I took a few years ago with the Fuji underwater camera.
I was snorkeling in a bay when the turtle (who was two or three feet long) swam by, and the kids are in the hotel pool.
For both shots I was close to the surface, so there was plenty of sunlight to help keep the colors intact.
You can improve the images greatly (like I did) by scanning them into your computer and using a photo-editing program to adjust the color balance.
A long time ago someone here posted a wonderful tip for underwater shooting that helped me to improve my photos.
They said that you shouldn't focus all of your efforts on trying to take pictures of fish, because they're just fish and unless you have a great underwater camera with a close-focusing lens and an underwater flash, it probably won't look like much.
The underwater photos that you'll end up treasuring over the years will be the ones with your friends and family in them. (Yes, that turtle is my uncle.) So if it's possible, get your loved ones out in the water and get some shots of them. Ideally, you can have them swim WITH the fish and take some pictures of that!