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Comment by sandworm101 | Hacker News Reader

Not stealth. Far to many flat 90/45* surfaces and corners. Nobody with any understanding of radar was involved in the design of that thing.

Not supercavitating. Supercavitation is based on cavitation, not sucking down air from the surface. http://en.wikipedia.org/wiki/Supercavitation. And the amount of energy needed to create a supercavitation void around those hulls ... The Shkval is essentially an underwater rocket and it still uses exhaust gases to top up the bubble in which it flies (see the little holes near the nose) http://en.wikipedia.org/wiki/VA-111_Shkval.

Not a hydrofoil. No foils. It looks to be a SWATH hull (Small Waterplane Area Twin Hull) another great Canadian invention. http://en.wikipedia.org/wiki/Small-waterplane-area_twin_hull

Who did this guy know at Businessweek to get this sales pitched turned into an "article"?

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Won't an air envelope reduce friction as much as a vapor envelope?

RE: SWATH: their patent http://www.rexresearch.com/sancoff/sancoff.htm discusses hydrofoils and SWATH as prior art [0182], [0183], but fails to describe how their "buoyant tubular foils" (BTFs) [200] are different.

They're pontoons on movable outriggers. Novel, but useless. An air envelope would certainly reduce friction but would basically kill buoyancy. Big metal tubes don't float in air. So without any real foils/wings to generate lift, even if a bubble could be formed, the pontoon would literally fall to the bottom of the bubble.

Supercavitating hulls (ie the ShVal torpedo) suspend themselves within a bubble via their noses. They are moving so fast that the nose, the only spot where the torpedo touches the water, provides enough lift to keep the thing in the bubble. But you need rocket-like accelerations to keep this going.

From their patent "whereby to provide propeller generated super-cavitated water flowing from the propellers and thence along an outer surface of said vehicle;" WTF? There is no such thing as super-cavitated water. Cavitation presupposes a CAVITY, a void ... something other than water. Maybe water with bubbles? Prop wash?

http://www.google.com/patents/US20120097086

Another noteworthy design deviation (compared to run of the mill SWATH) of this vessel is the dihedral angle of the pontoon supports. Based on the wake behind the vessel, it appears that the pontoon supports might even be providing some lift. This could provide a hydrofoil like lifting effect, but the design of those supports wouldn't make a terribly efficient foil. The aspect ratio is all wrong. Hydrofoils typically have a very short chord, because water generates plenty of lift without a high aspect ratio.

This thing just sounds like a whole lot of smoke and mirrors. Hopefully the guy can sell it to some Hollywood studio to use in Mission Impossible 10 so he can recoup some of his investment.

It also reminds me of this Canadian invention: http://en.wikipedia.org/wiki/HMCS_Bras_d'Or_(FHE_400)

Ya, but that ship was an actual hydrofoil. The foils act like wings to generate lift from movement. The thing in the OP uses movable pontoons, buoyancy, to haul itself up regardless of speed.

Note also that real hydrofoils angle their foils in parallel to the hull. It's essentially a dihedral effect like that of an airplane. As the ship lists one way, the foil on the downward side pushes more directly upwards, righting the ship. The 'foils' on the OP are mounted in the opposite manner, generating opposite effect. If they generated any actual lift the ship would flip instantly.

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