Taking lessons from narco-terrorists and al-Qaeda, Iran has relaunched an effort to intimidate western shipping in the Persian Gulf. Using the Houthi insurgency as a cover, a new generation of go-fast unmanned bomb boats threatens the shipping lanes and could be used even against warships.

In the latest near-encounter, the British warship HMS Duncan (D37) was proceeding through the Red Sea last Saturday night after passing through the Suez Canal when it almost crossed paths with a Houthi bomb boat called Blowfish.

The Blowfish is a fiberglass vessel 9.8-meters long (32 feet) that runs at 35 knots (40 mph) and is powered by two 200-horsepower outboard motors. The Blowfish was spotted by Saudi navy ships. But it was never seen by those on the Duncan.

Frigate stymied attack

This was the second recent challenge to British warships. The first was a week before the HMS Duncan incident when the British warship HMS Montrose (F236) warded off an intimidation operation run by Iran’s Revolutionary Guard Navy against the British oil tanker Heritage.

Iran launched five manned fast-attack boats in a swarm to try to take control of the tanker, but the operation failed thanks to intervention by the Montrose, a Type 23 Duke-class frigate.

The British frigate is well equipped with missiles and torpedoes and also has more guns than a typical US frigate, including two 30mm DSM30M MK2 Bushmaster Gatling canons on automated mounts. The Montrose was first equipped with this rapid-fire cannon system in 2009 in order to ramp up the frigate’s ability to deal with fast-boat swarming-type attacks.

The Iranians thought better of sticking around with the Montrose on the scene and departed the area.

The Blowfish is more of a challenge, although it has a relatively short operational range of about four miles, probably limited more by the need to visually control it from the shoreline than limitations on fuel capacity.

It is a fiberglass, Kevlar and carbon-fiber boat with two large outboard engines, very similar, if not identical, to the go-fasts narco-terrorists have been using to run drugs, mainly cocaine from the cartels in Colombia up to Mexico, where the drugs are smuggled overland to the United States or by ship to Europe.

Go-fasts can reach speeds of 80 knots (150 km/h, 90 mph) in calm waters and more than 50 knots (90 km/h) in choppy water. Most narco-terrorist go-fast vessels have a two to four-man crew. They are typically used mainly at night and are hard to detect.

IRGC go-fast boats

The Navy of the Islamic Revolutionary Guard Corps produces go-fast boats in Iran. The technology is simple and this relatively low-tech vessel is stuffed with explosives, usually C-4 in the form of a shaped charge in order to penetrate the hulls of larger commercial and military ships.

The USS Cole was hit by a bomb while refueling in the port of Aden in Yemen in October 2000. About 17 sailors were killed by two Yemeni militants with al-Qaeda. Photo: AFP/Navy handout

In October 2000, a manned-version of the same kind of fiberglass boat stuffed with 400 to 700 lbs of C-4 explosives struck the USS Cole (DDG-67) in Aden Harbor, killing 17 sailors and injuring another 39. The Cole attack was an al-Qaeda operation and allegedly the boats were purchased from foreign suppliers.

Prior to the successful attack on the Cole, al-Qaeda launched a suicide-boat attack in early January 2000 on the USS The Sullivans (DDG-68), but the attack boat sank, apparently in rough water.

Al-Qaeda was more successful in a suicide-boat attack on the oil tanker MV Limburg, causing damage and fire on the tanker and a serious leak of oil. One crew member was killed and 12 others hurt in the explosion and fire.

The Houthis have also been busy with unmanned boat attacks.

On January 30, 2017, a Houthi unmanned bomb-boat attacked the Saudi Arabian Navy frigate al-Madinah (702), most likely using a Ya Mahdi unmanned boat. The attack took place near the Yemen coast along a Houthi-controlled area near the Bab-el-Mandeb Straits. Two Saudi sailors died and the ship sustained significant damage.

The Ya Mahdi go-fast is a knock-off of a British type 51 Bladerunner speed boat. At least one Bladerunner was illegally sold to Iran in a sophisticated smuggling operation.

The Bladerunner was a 16-ton “yacht” powered by two 1,000-hp Caterpillar engines that could reach a speed of 60 knots (69 mph). The successful smuggling operation was well-detected by Western intelligence, but the continued supply of engines and other equipment for Ya Mahdi construction has never been satisfactorily explained.

Whether relatively sophisticated fast boats like the Ya Mahdi, or simpler but equally effective craft like the unmanned go-fasts that shadowed the HMS Duncan, these high-speed vessels present a serious challenge because they are hard to spot in the water.

One of the techniques used by narco-terrorists that no doubt has found its way to their Iranian counterparts is the design of hulls that are relatively streamlined and narrow, reducing any visible wake from the vessels. Because they are primarily fiberglass and running close to the surface, picking them up on radar is also difficult.

The best way to detect them is with modern electro-optical sensors, but even these sensors have a spotty performance record against go-fasts. The US Coast Guard and US Navy have known this for some time as they continue to try and track these vessels in the Pacific and the Caribbean in the US’ War on Drugs.

It might be reasonably asked if the US Coast Guard can be of help in the Red Sea and Persian Gulf, since they have long experience in going after go-fasts.

The frustration surrounding this new type of asymmetric warfare was not lost on President Trump. He reportedly said: “So, these boats, they get in, they come in really fast, they come in really close … and they might have explosives on them and we don’t even know. Can you believe this? And we don’t do anything?”