For the film shooters migrating to digital, here's an option that may help reduce you initial outlay. Subaquatic Camera will retrofit the Nikon SB-105 with an optical fiber and add the housing mounts for it. The cost is around $130 for the operation including all parts and labor, which is just slightly more than the fiber and mounting costs of current digital strobes. There are two major drawback to this setup. One, the SB-105 have no pre-flash canceling circuit, and will only work with a camera that can fire a flash trigger without a pre-flash like the Olympus 5050. Also, this strobe only has full, 1/4 and 1/16  power settings and will require changing strobe positions to fine tune exposure.