The prawn trawler Sustain slid onto the rocks at Rubha Camas a' Mhaoraich at 1946 on 16 November 2023, ending its fourth day of an eight-day fishing run. The vessel, which had just passed through the Summer Isles and Carn Skerries, was making 7.7 knots when it struck the seabed near the entrance to Loch Broom. All crew members survived the incident, but the ship was later declared a constructive total loss and dismantled by specialists in early 2024.
The Marine Accident Investigation Branch (MAIB) pinpointed the cause: the skipper fell asleep in the wheelhouse. He had been awake for over 21 hours prior to the incident and had accumulated a 7.8-hour sleep debt over the four days of the run. The report notes that the engine exhaust ran through the small wheelhouse, making it warm and conducive to drowsiness. Crucially, no watch alarm was fitted to detect inactivity and sound an alert.
This oversight was not an accident of ignorance. The vessel's safety risk assessment, last reviewed on 21 June 2023, explicitly identified the risk of ineffective watchkeeping leading to grounding. The prescribed control measures included ensuring a watch alarm was fitted and working correctly. The MAIB found that these measures were not implemented. Marine Guidance Note 313(F) recommends such alarms on all vessels where a single person keeps the navigational watch.
The navigation failed in multiple ways. The plotter used did not meet Mini-ECDIS standards and lacked navigational warning functionality. The autopilot followed magnetic compass courses rather than interfacing with the plotter, meaning it couldn't correct for drift. Data showed that the course set after Eilean Dubh would have passed only one cable clear of dangerously shallow water, a margin that vanished as the vessel drifted three degrees to starboard.
The MAIB cites a similar incident involving the fishing vessel Golden Promise, which grounded on Stroma in 2011 under nearly identical circumstances involving an asleep skipper. The branch is likely to use the Sustain case to press for stricter enforcement of watch alarm fittings on small commercial fishing vessels in the UK, addressing the gap between identified risks and actual safety equipment on board.