Steven Loui, president of Navatek Ltd., shows off a few samples of the company's new technologies.
Rocking the boat world
Navatek Ltd. has impressed the Navy
with a new type of ship design
Local ship-design firm Navatek Ltd. usually tries not to make waves. But that might not be possible for much longer.
The company, which designed and built the Navatek I and II dinner-cruise vessels and other twin-hulled craft made to slice through the sea, has received a boost from successful U.S. Navy tests of a new in-house ship prototype.
The prototype's patented technology, called HYSWAC -- for Hybrid Small Waterplane Area Craft -- is being described by experts as a breakthrough in ship design. The results of the tests, conducted in Hawaii waters this past winter, raise hopes for widespread commercial and military application of the design.
The 160-foot, 320-ton prototype is a refitted Navy research vessel. Re-dubbed the Sea Flyer, it features an underwater wing-like appendage -- a "lifting body" -- that spans the width of the ship and joins to the twin hulls by a pair of struts. Functioning like an airplane wing, the aerodynamic device gains lift as the ship accelerates, raising the vessel largely clear of the waves and dramatically increasing stability.
The result is a faster and smoother ride even in heavy seas.
"That's sort of the holy grail for naval architects," Navatek President Steven Loui said.
Navatek's Hybrid Small Waterplane Area Craft "Seaflyer" takes a trial run off Honolulu.
Heavy interest
The Navy, which liked Navatek's design concept so much that it funded the bulk of the prototype's $18 million cost, is considering the design for its planned new generation of coastal combat ships, which can allow helicopter landings and more easily deploy personnel and devices over the ship's side due to the added stability.The Coast Guard and "a half-dozen" other unnamed parties eyeing defense-related uses also are interested, Loui said, and Navatek is talking with the U.S. Department of Transportation, which is interested in a prototype of a "seasick-free" ferry.
The trials, conducted for the Navy's Office of Naval Research in heavy seas, showed that the vessel barely slowed from its cruising speed of 28.5 knots and remained stable despite conditions that would have caused a traditional ship to founder. The ship also can bank into faster, tighter turns due to airplane-like control flaps on the lifting body.
"It's a remarkable achievement," said former Coast Guard Commander George "Hank" Teuton, who piloted the vessel during the tests. "It didn't matter whether we were heading into the seas or abeam to the seas, the vessel remained absolutely stable."
The company, founded in 1979, launched the Navatek I in 1990 and crafted a number of other vessels with advanced hull designs. Navatek is a subsidiary of Pacific Marine Supply, which was founded by Loui's father in 1944.
The big idea
In the late 1990s, Loui hit upon the idea of using an underwater "wing" to eliminate the sort of design limitations in ships that have blocked the commercial feasibility of an interisland ferry system.Hydrofoils travel fast by rising high above the water but can carry only small passenger loads and are unstable at slow speeds. Ships like the Navatek I employ a more stable hull design but travel slowly.
The HYSWAC tests have found a middle ground, said Gary Jensen, director of the Navy ONR's mid-Pacific branch.
"It was thought you could only be stable and fast with a really big vessel, but this shows you can do it (with small to mid-size ships)," he said.
Perhaps more importantly, says Loui, the ship performed exactly as predicted by Navatek's computer modeling, lending the company a credibility that will prove invaluable when seeking federal grants for future designs.
"So if I now go to these guys and say I want to do a vessel that goes 50 knots, people won't laugh at me. This kind of validation is priceless," he said.
Even bigger
Loui expects that credibility to come in handy when seeking funding for the company's next project: An $8 million, 50-foot prototype now under construction in a California shipyard that will simulate the technology's potential on much larger, single-hulled vessels.The Sea Flyer was essentially a retrofit of an existing vessel, allowing Navatek to build it at Honolulu Shipyard Inc. But Loui said he's likely to license the technology to any interested parties to build themselves because the yard is insufficient for full-scale production of a HYSWAC vessel.
However, manufacturing of the drive-control mechanism could be kept here, he said.
Loui said he also is considering building a couple of HYSWAC-type vessels for local tourist uses, such as ferrying visitors to Kauai's Na Pali Coast, where a stable vessel would be required due to often rough seas. He said the company would likely sell or lease the vehicles to an operator.
