Digital Photography underwater!!!

Toni Frissell

Other examples -Michael Muller

More inspiration 
http://www.underwatersculpture.com
http://www.creativelite.com/2012/12/40-beautiful-underwater-model-photos/

background sheets
clamps and weights
swim goggles/ snorkels
life vests
flashes
waterproof bags for cameras
garbage bags for wet clothes
suits dresses