The Seabex One kit  is a model of a North Sea diver support vessel.  The model has several interesting features such as a moon pool, working fire nozzles, a working crane, a helicopter with spinning rotor blades and most interestingly of all, 4 SPPS thrusters that make the boat highly maneuverable.  That is a good thing since the boat is 57 inches (1450 mm) long.  The kit was designed from the original ship's blueprints and looks to be pretty accurate.