Solong and Stena Immaculate Interim Report: MAIB Reveals Details of Deadly Collision Off U.K. Coast

The UK Marine Accident Investigation Branch (MAIB) has released an interim report detailing the serious maritime incident involving the Portuguese-flagged container ship Solong and the U.S.-flagged oil/chemical tanker Stena Immaculate, chartered by the U.S. Navy’s Military Sealift Command and operated by U.S.-based Crowley.

The collision occurred on March 10, 2025, approximately 14 nautical miles northeast of Spurn Head near the Humber Estuary, resulting in one fatality on board the Solong.

The incident unfolded when Solong, traveling at approximately 16 knots, struck the anchored Stena Immaculate’s port side at 0947 hours. The impact breached the tanker’s No.7 port cargo tank, causing aviation fuel to spill into the sea and onto Solong’s bow. The collision’s force generated enough heat to ignite the fuel, with the fire subsequently spreading to containers aboard Solong.

“The visibility in the area north of the Humber light float was reported to be patchy and varying between 0.25 nautical miles and 2.0nm. Neither Solong nor Stena Immaculate had a dedicated lookout on the bridge,” the report states.

At the time of the incident, Stena Immaculate was carrying 220,204.5 barrels of aviation fuel and had been anchored since the previous evening, following instructions from Associate British Ports (ABP) Vessel Traffic Services Humber.

According to the report, Solong was operating on a fixed trade route in the North Sea between Rotterdam, Grangemouth, and Hull, carrying various containerized cargo, including dangerous goods.

The interim report provided these details about the Solong’s actions before the collision:

• Departed Grangemouth, Scotland at 2000 on March 9, 2025
• The master was on watch until around 2300, then handed over to the second officer
• At 0130 on March 10, passed Longstone Lighthouse and changed course to 150°
• Solong maintained this course except for a slight deviation at 0345.
• At 0700, the master returned and took over as lone watchkeeper in patchy visibility conditions (0.25-2.0 nautical miles)
• At 0947, collided with the anchored Stena Immaculate while traveling at 16 knots

“Both Stena Immaculate and Solong’s crew abandoned to lifeboats and were subsequently recovered by the efforts of local boats and emergency responders, coordinated by His Majesty’s Coastguard,” the report indicates.

Tragically, Solong’s able seaman Mark Pernia, who was reported to be in the forecastle area during the collision, has not been found and is presumed dead.

The MAIB’s ongoing investigation will focus on several critical aspects.

“The investigation will encompass the navigation and watchkeeping practices on board both vessels; manning and fatigue management; the condition and maintenance of the vessels involved; the use of the offshore area as an anchorage for vessels waiting to enter the Humber Estuary; and the environmental conditions at the time,” the MAIB states.

Currently, both vessels are undergoing salvage operations while authorities evaluate the extent of environmental damage from the incident.

The Solong’s captain, Vladimir Motin, has been charged with gross negligence manslaughter.

The Stena Immaculate’s U.S.-based manager, Crowley, issued the following statement on the release of the interim report:

“The report confirmed that the Stena Immaculate’s Second Officer was on watch, beginning a 12-hour lookout shift just before midnight, during which patchy visibility was reported in the area. 

“It is important to note that watch requirements for vessels at anchor are different from ships that are underway. The Stena Immaculate was operating in compliance with applicable watch-standing safety regulations and Crowley company policies for an anchored vessel. We are confident that the forthcoming comprehensive investigation report will clarify the facts and circumstances of the incident, demonstrating that Crowley exercised appropriate vigilance.  

“At Crowley, safety is rooted in everything we do – from our people, operations and communities we serve. We are extremely proud of the 23 mariners of the Stena Immaculate, whose bravery and operational focus ensured that fire monitors were active in order to provide boundary cooling water. Their actions resulted in limited impact to just one of the 16 cargo holds and the remaining cargo, minimizing impact to the environment and protecting their lives.”

The MAIB notes that this is an interim report, and new evidence may emerge that could alter the current understanding of the incident. The incident is also under investigation by authorities in the United States and Portugal.

The full interim report can be found here.

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