Nikon
Even in the digital realm, the Nikon Nikonos V Camera soldiers on as the most complete interchangeable-lens underwater-specific camera system in the world. It just uses 35mm film. With 5 lenses from fisheye to telephoto, your photos will only be limited by your opportunities and creativity.
The Nikonos V is extremely durable, with simple to operate controls that are oversized and highly visible. It can function without batteries, and only needs simple lithium button cell batteries which last a long, long time. The Nikonos V uses the Nikonos system of lenses and lighting/macro solutions, which includes the optional TTL Speedlight flashes.