Ferry consumes its own waves
A new high-tech ferry launched this summer from a San Diego yard will be delivered to Venice this fall. Its designer and builder hope that the 65-foot Mangia Onda (Wave Eater in Italian) will assist the ancient city's preservation officials in reducing damage to buildings caused by wave action.
Mangia Onda is designed to eat the waves it creates, according to Bill Burns, member manager of Mangia Onda, Inc., of San Diego. Burns said the new vessel, the first of its kind in the world, combines certain elements of multihulls, surface-effect vessels, and monohulls. "It has the fine forward entry of a mulithull so that the bow cuts through waves. And, like a surface-effect vessel, air is captured beneath the hull, providing cushion, and it has the stable platform of the monohull," Burns said. "The hull captures the bow waves and channels the water back, where air is then mixed in. The air-water mixture reduces friction, helps lift the boat out of the water, and helps dampen the stern wave." He said that the vessel, despite traveling at 30 to 35 knots, produces no wake, which are so damaging to the fragile buildings of Venice. Mangia Onda will serve as the main passenger ferry between Venice's airport and the city.
Burns said that this style of vessel does not produce solitons, the energy-packed waves apparently generated by high-speed ferries, that have recently caused injuries and deaths when the waves traveled into shallow water, built to great heights, and broke.
A likely explanation for the vessel's small wake, Burns said, is that the Mangia Onda does not displace as much water as high-speed cats and that it re-circulates and diffuses the wave-making energy produced by the hull as it speeds through the water.