Catamaran Boats have always been known to be very stable while sitting still on the water or moving at speeds, simply because you have 2 hulls. One hull enhances the other, meaning that as one hull is raised or lowered due to water movement, the weight versus the flotation of either hull are trying to stabilize each other. Cat Hulls displace only about 1/3 of their weight which enables the boat to run across the top of the water - not through it.