PapaBear has that one on the money! Even an amature photographer can take beautiful shots with inexpensive equipment.
I personally use a Canon Powershot A80 w/ Canon`s prescribed UW housing for my footage. I had to find out why my lake shots were so murky and green. It`s a simple fix if it`s a digital camera.
My blog for UW photo tips gives you some good info on just this type of issue: http://www.divebuddy.com/public_blog.asp?StoryID=295
I noticed that some of the pics on your site had a green tint to them (I have the same issue in the lake). You simply need to adjust the manual hue settings for the conditions you are diving in. If you have a slate, you`ll learn to appreciate it that much more.
If you`re using Ebay gear on those shots, you`re doing quite well for inexpensive gear. Just takes learning how to fine tune the equipment to get what YOU want.