Audi trimaran concept by Stefanie Behringer

While hybrid propulsion is becoming more and more common in cars – concept cars especially – the application on the water has remained somewhat more limited. Some larger motorboats might incorporate sideways electric thrusters to help with docking, but that's by and large the extent of it.

As you might have guessed, however, this is no ordinary motorboat. For starters,- it doesn't actually exist – it's a design exercise. One created by German grad student Stefanie Behringer with input from Audi's design department. It's designed around a trimaran form – that is, a boat with three hulls that optimizes stability without the drag in aquadynamics that goes with a wider hull. Which picks up where the R8-inspired catamaran (that's two hulls to you landlubbers) and the nautical theme of the Q7 Coastline concept left off and takes the idea even further.

Attached to the center hull are two narrow outriggers that each house an electric-powered jet ski. The personal watercraft can (at least, in theory) be deployed as toys or tenders, but when docked inside the the outriggers supplement the main engines for trolling (that is, maneuvering around the marina) at up to 8 knots (9.2 mph) or accelerating. Oh, and the main engines? A pair of (presumably marinized) V12 TDI turbo-diesels with 500 horsepower apiece. Combined with the pair of 100-hp electric jet drives, that makes for 1,200-hp of thrust, which, with the boat's slender shape, is estimated to be good for 40 knots (46 mph).