I got a lot of help from this forum in selecting some equipment and then trying some easy freediving. Here is a collection of pictures from my Hawaii trip this summer:
www.miklwald.smugmug.com. Used a Nikon D70 with kit lens in an Ikelite housing with dome port. Depth to about 30 feet. Available light - no flash. Best seen in slideshow mode with your pointer on the advance button, there are a lot of them.