http://scubahack.com. Want to write the first "Hello World" program underwater? iDive is an underwater iPad casing that supports full touchscreen functionality up to depths of 100 ft.
#scubahack is a hackathon for iDive. We seek engineers, designers, domain experts, and folks that just generally get important things done to create the first round of iPad apps for scientists, recreationalists, and others for use underwater. Developers will own what they create over the weekend.
This event is invite only. Apply at http://scubahack.com.