Scott H said:SNUBA allows you to dive under the water with a long regulator hose from the tank that floats on the surface.
If anyone gets a chance to do SNUBA, it really is a kick! We did it last Jan '04 in St Thomas. I'd never done anything like that, and had a blast.
I have asthma and had to get a note from my doctor. We went down about 12 feet, and I had a great time! I know that I couldn't go much farther though.