By Al-Fassel | 2024-04-24

After launching a failed attack using an unmanned surface vessel (USV) on January 4 -- the first amid the ongoing Red Sea crisis -- the Houthis have deployed sea drones and other seaborne weapons on numerous occasions.

The use of sea drones, along with the group's first observed use of an unmanned underwater vessel (UUV) since their attacks began in October, represents an evolving threat, the US military said.

The initial USV -- a low-profile vessel deployed from Houthi-controlled territory in Yemen -- transited about 24km out into international shipping lanes in the Red Sea before detonating a few miles away from ships, Naval News reported January 9.

The following month, the US military successfully destroyed a UUV -- an underwater weapon that is similar to a torpedo but slower -- in a February 17 strike.

Days earlier, US forces interdicted a shipment of weapons destined for the Houthis from Iran that included UUV components.

The seizure connected the Houthis' UUV threat to Iranian-supplied vehicles and techniques, the US Naval Institute reported.

The Houthis have used crewed and uncrewed vessels for one-way attacks before, but the introduction of a one-way attack USV to harass commercial shipping in the Red Sea "is of concern," Vice Admiral Brad Cooper of US Naval Forces Central Command said at the time.

As predicted, the Houthis have continued their aggression in the Red Sea and Gulf of Aden, on April 18 announcing they had attacked 98 vessels to date, AFP reported.

US and coalition forces have continued to intercept and destroy the Iran-backed group's USVs on at least a dozen occasions, to protect freedom of navigation and make international waters safer and more secure.

Houthis' maritime arsenal

USVs are a key part of the Houthis' maritime arsenal, International Institute for Strategic Studies missile expert and research fellow Fabian Hinz told PBS.

They have regularly been used as suicide drone boats that explode upon impact.

Most of the Houthis' USVs are likely assembled in Yemen but often fitted with components made in Iran, such as computerized guidance systems, Hinz said.

The Houthis did not have USVs before their 2014 coup in Yemen, and have taken technology for the sea drones from the Iranian regime and its Islamic Revolutionary Guard Corps (IRGC), a retired Yemeni general told Al-Fassel.

These boats are typically about seven meters long and weigh up to a ton, he said. They can travel at a speed of 40 knots, and some are equipped with Global Positioning System (GPS) technology to guide them toward their targets.

The damage they cause on impact is "enormous and multifold," he added.