Halleck-Class Hovercraft

Though as always, Muad'dib's fanatic Fremen legions provided the hand-to-hand killing power, on such watery planets as this, the expertise of House Atreides troops in sea power was also essential. The Atreides brought naval technology perfected in their ancient wars on Caladan, including the prototype for the Halleck-Class hovercraft, a light patrol and transport vessel. The Halleck-Class was a surface-effect ship with rigid twin hulls and an air cushion. At low speeds, the vessel was supported by the buoyancy of its two hulls, like a catamaran. At high speeds, the rear propeller pods were lowered into the water and the air cushion was inflated between the hulls, trapped by skirts across the prow and stern. The air cushion reduced drag, allowing high rates of speed, while the rigid hulls provided a higher degree of lateral stability than a traditional hovercraft.

 

—from Tools of War: A Study of Atreides Military Technology

Done