Only crazy people and scientists get in thre water with Great White sharks. If you are among the latter, you might want some means of propulsion (ideally of the shark-prrof variaty) which is where a special type of midget submarine comes in. Designed with Euronaut's Carsten Standfuss (submarine builder, expert and sub historian), the SOV (Shark Observation Vehicle) is a one-off specialist device. The sub patrolled Shark Alley, a narrow passage between Dyer Island and Geyser Rock off South Africa in 2006-7.

I've heard that you can defend against a shark attack by punching it on the nose! Apparently that is 100% true. Still, this guy has balls od steel.

Like most private subs it had a short life in the water and has since been retired to the Nautineum Dänholm museum (Link)

The SOV employed a tandem 'chariot' layout with two divers encased in a lightweight frame to prevent sharks from snacking on them. Three thrusters were mounted outside the hull with the forward pair being steerable. The cylinders running across the hull either end of the crew compartment contain ballast tanks and batteries.

Links:
Shark Project (DE) HERE