This catamaran was built by martijn boon from andijk – the netherlands. martijn is a welder and machinebuilder who also likes to design and built special. Open/dayboat, free sailboat plans hobby kat. everyone who digs boating has heard of the hobie cat, the sleek little catamaran that burst on the scene and captured the. For the newly initiated, a "pacific" or "windward" proa is basically a multihull sailboat with a single float or outrigger for stability. under sail, the outrigger is.