The Tokina AT-X 116 PRO DX is a new lens available for Nikon as well. It has an f/2.8 aperture. I did have the lens only for a day and was not able to use it underwater; I was impressed with its optical qualities. You will find a good review here
http://www.kenrockwell.com/tokina/11-16mm.htm. While the D80 is not mentioned, it should work on the camera, since it is working on the D70. Price is around $500+