Bulker Encounters Swarm of Unmanned Boats off Yemen

In a concerning new development for the security of merchant shipping in the Red Sea, a bulker has reported an encounter with a large swarm of suspicious small craft off the coast of Mokha, Yemen - some of which appeared to be unmanned. 

For at least the last seven years, Yemen's Houthi rebels have been developing unmanned waterborne improvised explosive devices (WBIEDs), with help from the military forces of Iran. The Houthis have used these bomb boats with varying degrees of success, first against Saudi maritime interests and more recently against international merchant shipping. A thinly-disguised "fishing boat" struck and disabled the bulker Tutor in the Red Sea on June 12, killing one crewmember and flooding the engine room. The group returned with another bomb boat to inflict further damage, and Tutor ultimately sank (after additional Houthi intervention). The group also claimed a strike on the bulker Seajoy on June 27.

In these previous encounters, Houthi remotely-controlled bomb boats have attacked one by one. On Sunday, the bulker Summer Lady informed UK Maritime Trade Operations (UKMTO) that she had been approached by a flotilla of suspicious small craft, composed of a mixture of "fast boats and smaller kayak-type boats." Multiple vessels in the group appeared to be uncrewed, a sign of potential suicide-drone capability. 

The master of Summer Lady reported that these suspicious watercraft remained near the vessel for an hour before departing the area. The bulker was unharmed, and it headed for its next port of call. 

Later in the day, U.S. Central Command announced that American forces destroyed three unmanned surface vessels in the Red Sea. CENTCOM's announcement did not specify whether these unmanned boats were related to the Summer Lady encounter, but said that the targets "presented an imminent threat to U.S. and coalition forces, and merchant vessels in the region."

On Sunday, a Houthi spokesman released a video showing the first glimpse of the group's operating tactics for remotely-controlled boats, below. In the demonstration, a manned speedboat with crewmembers maneuvers aggressively between a series of buoys (time marker 1:30). At a predetermined location, the operators jump off the stern, and the boat continues to maneuver on its "own," with remote guidance.