The U.S. Navy Might Ditch All Of Its Shallow-Water Combatants

The U.S. Navy has exactly 25 patrol boats that are small enough to sail in the shallowest stretches of the Persian Gulf where Iranian forces lurk.

All of these vessels—13 Cyclone-class coastal-patrol boats and a dozen smaller Mk. VI patrol boats—are on their way out of the fleet. And the Navy’s plan for replacing them is full of holes.

The Cyclones joined the fleet between 1993 and 2004. The 179-foot boats are heavily armed for their size with machine guns, grenade-launchers, two 25-millimeter cannons and twin quad launchers for Griffin surface-to-surface missiles. Their crews can fire Stinger surface-to-air missiles to protect the boats from drones, helicopters and low-flying airplanes.

Three Cyclones sail from Mayport, Florida for training. The other 10 are based in Manama, Bahrain, giving them easy access to the Persian Gulf.

They’re not alone in Bahrain. The Navy’s coastal command also keeps three of its 12 Mk. VI boats in Manama. The 85-foot Mk. VIs, the oldest of which joined the fleet in 2016, bristle with no fewer than three .50-caliber machine guns and two 25-millimeter cannons.

There are other Navy forces in the Persian Gulf region including drones, patrol planes, minesweepers. Amphibious and carrier groups frequently pass through. But the Cyclones and Mk. VIs are there every day. And they’re both small enough—respectively drawing just 7.5 feet and four feet—and tough enough to defeat Iran’s armed speedboats.

But the Navy is about to begin decommissioning the Cyclones and Mk. VIs. The three Cyclones in Florida are scheduled to leave the fleet in March. The Navy could remove all the Mk. VIs this year, according to a planning document The War Zone obtained.

The Cyclones are old. The Mk. VIs with their complex propulsion systems reportedly are difficult to maintain. But it should be a straightforward process to replace both types with similar new vessels. Countless shipyards all over the world build patrol boats, offshore patrol vessels and corvettes that, in principle, could take over the Navy’s patrol mission in the Persian Gulf.

But the Navy has no plan to replace the old patrol boats with new patrol boats. Instead, it has discussed deploying its much-maligned Littoral Combat Ships to the Persian Gulf alongside lightly-armed cutters from the U.S. Coast Guard.

The Coast Guard already keeps six 110-foot cutters in Bahrain. Each boat comes armed with a single 25-millimeter cannon and machine guns. The plan is for new 123-foot cutters, similarly armed, eventually to replace the aging 110s.

The coastal service has not announced any plan to expand its Persian Gulf patrol force. In any event, Coast Guard cutters are not combatants. They lack the armor, heavier weaponry and communications systems of Navy boats. Their crews don’t train for major combat.

The crew of an LCS does train for combat. And in terms of raw firepower, an LCS—for all its conceptual and design flaws—is an upgrade over a patrol boat.

An LCS fitted with an anti-surface-warfare mission module could sail into battle with a 57-millimeter main gun, two 30-millimeter cannons, 24 Hellfire missiles, a launcher for short-range surface-to-air missiles and eight Naval Strike Missiles for attacking large warships and targets on land.

An LCS also can support an armed helicopter.

But an LCS is too big for the shallower parts of the Persian Gulf where Iranian attack craft would be in their element. A Freedom-class LCS, 388 feet from bow to stern, has a draft of more than 14 feet—roughly twice what a Cyclone draws.

Equally problematic is the LCS’s height or “freeboard”—more than 20 feet from water to deck. An Iranian speedboat conceivably could get close enough to an LCS that the American vessel wouldn’t be able to depress its main gun low enough to shoot at the attacker.

That’s not an issue with a…