Solar power is free, although the implementation of it could very well be too expensive for most. Marvin the Martian here does not refer to a cartoon character, but instead is the name for an eco-friendly solar-powered boat. This 50' solar-powered cruising catamaran comes with 35 sq. meters of photovoltaic panels that are carefully affixed to its roof, providing the vessel with enough juice for it to be self-sufficient. Capable of making full use of its electrical propulsion that offers 30Nm autonomy at 5 kn, it can also achieve achieve a 487Nm autonomy at 9 kn with diesel propulsion. The fact that Marvin the Martian ain't bad looking either sure helps its case!