It’s been rough sailing for the U.S. Navy’s new Littoral Combat Ship. The speedy, warship has come under fire for being lightly-armed, weakly-built, undermanned, and prone to rusting—and yet, at the same time, way too expensive.

And in recent months, four of the 400-foot-long warships—half of the Littoral Combat Ships currently in commission—have suffered serious engine breakdowns, possible signs of systemic problems with the ship’s design and operating procedures.

As if that weren’t enough for the beleaguered vessel, David Giles, a prominent ship-designer, is accusing the Navy of stealing his concepts for a high-speed cargo ship and illegally applying them to the $500-million-a-copy Littoral Combat Ship.

The Giles isn’t alone. He has some heavyweight back-up in the form of Richard Garwin, one of America’s most eminent scientists.

If judge Charles Lettow from the federal claims court decides in favor of plaintiff David Giles, the U.S. government could have to shell out—well, potentially a lot of money. And it would be yet another black stain on the reputation of a warship that was supposed to transport the Navy confidently into the 21st century, eventually comprising nearly a fifth of the fleet.

Lettow is expected to announce his ruling some time in early 2017.

The 80-year-old, British-born Giles filed suit, via the company he founded, Fastship, in 2012. But the legal challenge has gone largely unnoticed in the mainstream press. He alleged in his complaint that the Navy violated two Fastship patents granted in 1992 and 1993 and which, taken together, describe a novel design for a faster, more efficient ship, one that essentially glides across the water—“semi-planing” is the technical term—rather than plowing through it.

The trick, according to one of Fastship’s patents, is to build a hull with a flattened rear underside and, while the ship is underway, shoot high-pressure water across the flat section. The combination of flat hull and water-jets creates “a dual component of lift,” the patent explains. And as the hull partially lifts out of the water, it moves faster than can a ship with a traditional V-shape hull that digs more deeply into the sea.

Most ships with V-style hulls can usually reach a top speed of just over 30 knots—roughly 35 miles per hour. But Giles told The Daily Beast that his company tested its “Prelude” semi-planing ship design at speeds up to 50 knots, way back in 1987.

Giles’s original aim was to build faster, more efficient cargo ships capable of hauling more than a thousand shipping containers apiece at a sustained speed of 38 knots. Normal cargo ships rarely exceed 23 knots, albeit with a larger load of containers.

But Fastship’s cargo concept eventually foundered, dragged down first by its high cost—$2 billion for the first four ships—and, finally, the volatility resulting from the 2008 global economic crisis. A partnership with Lockheed Martin seemed to offer Giles’s company a reprieve. In the early 2000s the Maryland-based defense firm was one of several companies competing to build potentially dozens of Littoral Combat Ships for the Navy.

Lockheed apparently wanted to make use of Fastship’s speedy-vessel concept. In 2002, the two companies formed what Giles described as a “strategic partnership.” Fastship handed over its design specs and test data, Giles told The Daily Beast, adding that Fastship had previously supplied the Navy with similar information in confidence between 1998 and 2000.

“Littoral Combat Ship” is actually the Navy’s catch-all term for two related classes of high-speed vessels. Only one of types apparently follows Giles’s design concepts. The other type is not subject to Fastship’s lawsuit.

In terms of size, water-displacement and speed, Fastship’s concept had a sweet spot. The Prelude design was 295 feet long, displaced 2,450 tons of water and—with all of Giles’s hull enhancements—maxed out between 40 and 50 knots of speed. In the early days of the Littoral Combat Ship program, that was too big and too slow. The Navy wanted a ship roughly half the size of Prelude and 10 knots faster.

Then in January 2003, the Navy’s preferences abruptly changed. The sailing branch brass decided it wanted a bigger, more robust ship—and didn’t mind if it was slower. Suddenly the requirement was for a ship roughly the same size, with around the same top speed, as Prelude. “It was like turning a Concorde into a 747,” Giles told The Daily Beast.

Actually, in keeping with this metaphor—it was like the Navy turned a Concorde into a 747… and Fastship had patented the 747. “Fastship describes its invention as a combination of a semi-planing mono-hull vessel, longer than 200 feet with a displacement in excess of 2,000 tons, which relies on hull design and water-jet propulsion to create a large ship capable of speeds exceeding 40 knots,” Judge Lettow explained in a 2013 court document.

In other words, if the Navy’s new Littoral Combat Ship matched the size and speed of the Prelude and made use of a flattened rear bottom hull and waterjets, it would overlap with Fastship’s patents. That’s the crux of Giles’s suit.

That’s exactly what happened, according to Giles—and yet Fastship never got paid. The U.S. Justice Department, which is defending the Navy, declined to comment for this story. Lockheed is not named inFastship’s lawsuit, and did not respond to requests for comment, either.

Lockheed dropped Giles’s company from its Littoral Combat Ship design team in 2004, after it had proposed to the Navy—and the Navy had agreed to buy—a vessel design that Giles said matched Prelude’s patented parameters but was too long and skinny for maximum efficiency. Since cutting the first contracts for Littoral Combat Ships in 2004, the Navy has spent billions of dollars on the Lockheed version of the class. USS Detroit, the fourth and latest Lockheed ship, commissioned on Oct. 22.

According to court documents, Fastship wrote to the Navy on April 11, 2008, informing the military sailing branch that the Littoral Combat Ships then under construction violated Fastship’s patents. The Navy wrote back on April 28, rejecting Fastship’s patent claim.

Fastship’s patents expired in May 2010, two years before the company sued. Giles’s firm claimed that the Navy built two LCSs prior to the patents’ expiration, but in June this year Lettow ruled that Lockheed completed just one of the speedy warships—USS Freedom—while the patents were active.

The lawsuit has dragged on for four years and could last months longer. In October, the Justice Department’s lawyer rolled out as an expert witness Donald Blount, an authority on high-speed vessels who claimed that any knowledgeable ship-designer could come up with Giles’s semi-planing system—and therefore Fastship’s patents were invalid.

The government also called Frederick Stern, an expert in fluid dynamics at the University of Iowa. Stern argued that the Littoral Combat Ship, as built, doesn’t plane as much as Fastship’s patented design did, and so never violated any patent.

To counter the government’s experts, Fastship’s lawyer deployed a secret weapon—Garwin, an 88-year-old physicist who, among other historic accomplishments, helped to design nuclear bombs and America’s first spy satellite.

Garwin told The Daily Beast via email that he’s known Giles since 1981 has found him “totally honest, perceptive and very intelligent.” Garwin argued that Giles’s innovations were not obvious to any reasonably-qualified ship-designer, as Blunt claimed—and that Stern’s computations were rife with errors.

In an email to The Daily Beast, Stern disputed that assessment, saying, "Yes we have very extensive/complete computational results supported by verification and validation studies: will have no problem publishing in peer reviewed archival journal once our results public released."

“Of course, the implications go beyond the details of the trial,” Garwin stated in a separate email, adding a quotation from Abraham Lincoln. “It is as much the duty of government to render prompt justice against itself in favor of citizens as it is to administer the same between private individuals.”

In this case, justice could mean yet another blemish on the fast-sinking reputation of one of the Navy’s newest warships. For his part, Giles told The Daily Beast he wants “at worst, fair and reasonable compensation.”

At best, he said, the lawsuit should “provide a better interpretation of our patents for U.S. and other navies’ ships.” So that maybe, in the future, someone can build a fast ship… that actually works.