By Chief Superintendent (ret.) Michael Cardash, Terrogence-Global
On June 12, 2024, the Liberian-flagged, Greek-owned bulk carrier M/V Tutor was targeted in the Red Sea by two unmanned surface vessel water-borne IEDs, forcing the crew to abandon ship a few days later and resulting in the ship’s sinking. The Houthis claimed responsibility for the attack one week after it was carried out.
Though unmanned WBIED attacks have been previously reported, this appears to be the first documented attack of a Houthi USV WBIED against a ship in the Red Sea since October 2023, the start of the Toufan Al-Aqsa / Iron Swords War in the Gaza Strip between the State of Israel and the Palestinian armed groups led by Hamas.
ANALYSIS
According to reports, the attack occurred about 66 NM (nautical miles) southwest of the Houthi- controlled port city of Al-Hodeidah, closer to the African coast of the Red Sea. The Tutor had completed a port call in Russia and was bound for Egypt, when it was struck in the stern by “a small, white-colored craft” with an estimated length of 5-7 meters, occupied by two mannequins. The subsequent impact and explosion caused severe flooding and damage to the engine room, leaving the Tutor unable to maneuver.
A USV WBIED approaching the Tutor
The USV WBIED and its two mannequins
The Houthis claimed responsibility for the attack on the same day it took place, stating Tutor was targeted using a USV WBIED, as well as “several UAVs and ballistic missiles.” In another statement released on June 15, 2024, Houthi military spokesman Yahya Sari asserted the Tutor was “expected to sink in the coming hours” and stated the attack was part of the escalation measures in support of the Palestinians in Gaza against the backdrop of the Toufan Al-Aqsa War. On June 19, 2024, the Houthis released a short video documenting the attack on the Tutor, which reportedly involved the use of two USV WBIEDs and what seems to be additional missiles.
The attack by the first USV WBIED
The attack by the second USV WBIED
Impacts by at least three missiles as well
The following weekend, between June 14 and 15, 2024, the crew abandoned ship and was airlifted by the USS Dwight D. Eisenhower Carrier Strike Group. According to a statement by US White House National Security Communications Advisor John Kirby, one Filipino crew member was killed in the attack and a Sri Lankan sailor was critically wounded. The ship was abandoned and eventually sank in the Red Sea.
The ship before it sank
The ship taking on water before it sank
Crew members airlifted to safety
Houthi maritime attacks against vessels, November 2023 – June 2024
ASSESSMENT
From the early stages of the Toufan Al-Aqsa (“Al-Aqsa Flood”) / Iron Swords War, which started in the Gaza Strip on October 7, 2023, with a large-scale surprise attack against Israel led by Hamas, the Yemen-based Houthi (Ansar Allah) movement has associated itself with the fighting in several phases of escalating actions “in solidarity with and support of the oppressed Palestinian people.”
According to analysts and observers, during the first half of 2024, the Ansar Allah movement carried out 57 attacks against vessels, and a total of 79 attacks since November 2023 (see the diagram above). However, other statistics suggested higher numbers, which likely include unconfirmed or unofficial attacks, as well as attacks that targeted the same vessel more than once.
The Houthis’ use of USVs is not new and has been documented since 2017, first to attack military vessels belonging to the Saudi-led coalition, such as in the attack on the Saudi frigate Al Medina in January 2017, and the attempted attack on the British HMS Duncan in July 2019, and then against oil tankers in 2020.
The Saudi frigate Al Medina targeted in January 2017
Saudi tanker Gladiolus targeted in March 2020
During this period, three types of USV WBIED platforms were documented in use by the Houthis:
- Shark-33 (a patrol boat modified for use as an USV WBIED)
- Blowfish (a dedicated USV WBIED)
- Fishing boats (USV WBIEDs disguised as fishing boats)
Shark-33 USV WBIED (top and center) with an SS-N-2 Styx anti-ship missile warhead (bottom)
Blowfish USV WBIED
Screenshot
As stated, the third model documented in the past is a fishing boat (skiff,) used mainly for the purpose of camouflage, containing an explosive payload previously documented as a box containing explosives, and later, as a metal barrel with an EFP warhead configuration. In our estimation, this type of boat was used in the attack against the Saudi tanker Gladiolus in March 2020, as well as against the M/V Tutor in June 2024.
On January 18, 2024, Project Masam – a Saudi humanitarian landmine clearance project in Yemen – recovered a USV WBIED previously used by the Houthis to target international shipping boats in the Red Sea.
The WBIED consisted of a basic blue wooden boat resembling numerous civilian fishing boats that sail along the Red Sea coast every day, which was found unmanned and floating near the coastal Bab al- Mandab village, southwest of the Murad area, where fishermen dragged it back to shore. It was left untouched for a month among other fishing boats. With no one claiming the boat, local villagers decided to inspect the vessel and spotted wires protruding from a hole in the hull of the boat, and they subsequently reported it to Project Masam.
After investigating the boat, bomb disposal technicians discovered the wires led to a large explosive payload hidden in a large container under the deck in the hull. It reportedly consisted of 25 kg of C-4 explosives and at least 50 kg of TNT, as well as 20- 25 liters of gasoline in containers.
According to Project Masam bomb disposal experts, the warhead had an EFP configuration, and was identified as a Houthi IED.
It has been estimated the USV WBIED was sent from Houthi-occupied port city Al-Hodeidah and was RC-controlled to sail along the coast toward Bab al-Mandab.
The fishing boat
The payload (left) with an EFP warhead (right)
On September 21, 2022, the Houthis unveiled, for the first time, during a military parade in Sana’a three types of USV WBIEDs, designated “Toufan” class USVs.
All three models have cockpits, arches, antennas, and a waterjet motor for propulsion. The Toufan-2 seems to have a glass dome camera and the Toufan-3 incorporates a different type of camera, possibly some type of a maritime forward-looking infrared (FLIR.) The Toufan-3 also has a Simrad HALO dome radar on its arch and in the lower part of the arch, another smaller white color dome component – possibly an autopilot compass.
In the Toufan-1, there is a single seat for one person, while the Toufan-2 and Toufan-3 have two seats, one behind the other.
Toufan-1
Toufan-2
Toufan-3
Comparison of technical info provided by the Houthis:
Comparison of technical info provided by the Houthis:
On June 21, 2024, the Houthis released a video in which they revealed information and documented their testing of the Toufan-1 USV WBIED. The video shows a boat that can be steered either manually or by RC control, targeting “a naval target” (a vessel) at sea.
Specifications of the Toufan-1, per the Houthi video:
- A locally produced USV WBIED capable of reaching high speed, maneuvering stealthily, and targeting close-range naval targets, both mobile and immobile
- Explosive payload (warhead): 150 kg
- Speed: 35 NM/h
Toufan-1
Toufan-1 with manual steering
Toufan-1 with RC-control steering in a test attack against a boat
A closer look at the results of the test attack
Toufan al-Mudammir (Lit. “Destructive Toufan,” an improved Toufan-3)
On the evening of June 21, 2024, the Liberian-flagged Greek-owned bulk carrier M/V Transworld Navigaton was attacked in the Gulf of Aden, 126 NM east of Aden city, while en route from Malaysia to Egypt. Explosions were witnessed in the vicinity of the vessel, which proceeded to its next port of call. The following day, the Houthis claimed responsibility for the attack, stating it involved the use of “ballistic missiles” against the vessel.
On June 23, 2024, the Transworld Navigator was targeted again by the Houthis, 65 NM west of Al- Hodeidah, off western Yemen’s coast, using a USV WBIED. The Houthis claimed responsibility for this attack as well. Documentation showed moderate damage was caused to the ship, with minor injuries reported as well by the US Central Command (US CENTCOM.) A USV approaching the vessel was also documented on video.
On June 30, 2024, the Houthis published a two-part video documentation of their new Toufan al-Mudammir. The first part documents the targeting of the Transworld Navigator with a Toufan al-Mudammir USV WBIED. Of note, the first frame of this part includes footage taken by a camera positioned on the bow of the USV. The second part of the video documents the testing of the USV WBIED at sea, which includes maneuvering between buoys. The testing covered both manual and RC-controlled steering, the latter ostensibly possible only at a limited range. The Houthis published the specifications of the new Toufan.
The USV WBIED reaches the Transworld Navigator attack
Toufan al-Mudammir specifications:
- Locally produced offensive USV with high destructive power
- Warhead: 1,000-1,500 kg
- Speed: 45 nautical miles per hour
Attack targeting the Transworld Navigator with a Houthi Toufan al-Mudammir USV WBIED
Toufan al-Mudammir with manual steering
Toufan al-Mudammir with RC-controlled steering
The array of weapons in the possession of the Houthis that threaten the shipping lanes in the Red Sea include surface(coast)-to-sea missiles, cruise missiles, ballistic missiles, UAVs, and a wide variety of USV WBIEDs.
The advantages of the USVs are mainly in their ability to accurately hit the targeted ships, especially since they are controlled using cameras located in the bow of the vessels.
Of note, the use of sailing vessels disguised as fishing boats with mannequins propped up in them is intended to prevent the vessel from being destroyed at a distance from the target, by creating confusion and doubt among the defending forces onboard the target as to whether the boat is on an offensive or innocent mission. ■
ABOUT THE AUTHOR
Chief Superintendent (ret.) Michael Cardash, Senior bomb technician and former deputy head of the Israeli police bomb disposal division, commanded bomb disposal units within the border guards and police during intense terrorist conflicts in Israel. Michael currently is the senior CIED analyst at Terrogence-Global, IED’s and authors the Terogence Möbius C-IED reports analyzing and assessing global IED-related technical and tactical intelligence.
Download PDF: 54-71 Michael Cardash – Houthi USV WBIED Attacks Targeting Merchant Ships in the Red Sea – COUNTER-IED REPORT, Autumn 2024
Counter-IED Report, Autumn 2024