The sinking of Diamond D

A straightforward coastal voyage in fair conditions turned to disaster when the experienced crew of a trawler deviated from their original plan.

A straightforward coastal voyage in fair conditions turned to disaster when the experienced crew of a trawler deviated from their original passage plan.

In August 2020, the wooden 15m (51ft) fishing vessel Diamond D capsized and sank after suffering hull damage and subsequent flooding while trying to uncross its towing wires. 

The prawn trawler had been on a routine relocation voyage when its two crew — the owner and skipper — decided to set their net to catch some fish for the owner’s restaurant, ahead of their arrival into North Shields on the River Tyne. Although the vessel would usually be manned by three crew for such an operation, the men felt confident that they could cope.  

However, during the trawl, the net picked up a heavy object and the towing wires crossed. The men then spent several tiring hours trying to untangle the wires. During their efforts, the boat took on a severe list and the trawl doors — large hydrodynamically-shaped metal plates that determine the horizontal spread of a net and its elevation above the seabed — hit the wooden hull several times, causing the planks and caulking to become dislodged.  

The bilge alarms, meanwhile, began sounding in the wheelhouse but went unheard by the two men who were busy struggling on deck — and not wearing their lifejackets. 

As Diamond D began capsizing, the men grabbed their lifejackets and an EPIRB (Emergency Position Indicating Radio Beacon), then launched the liferaft as the boat started to go under. 

Fortunately, the EPIRB provided rescue services with an accurate location for the liferaft and one hour later the men were eventually rescued, cold and shaken but unharmed. 

Investigation report

An accident investigation into the incident by the UKs Marine Accident Investigation Branch (MAIB) has concluded that Diamond D flooded, foundered and capsized almost certainly because the wooden hull was damaged when it was hit by the trawl doors, which allowed seawater to spread through the vessel as there were no watertight bulkheads to contain it. 

And while the MAIB report makes no specific recommendations, it does indicate that the incident is an important reminder to all fishing crews that they should always be prepared for flooding, should always wear PFDs (personal flotation devices) while on deck, and should regularly check all under waterline spaces for water ingress.

Lessons learned

The MAIB report notes that to undertake fishing operations safely, the Diamond D was normally operated by three crew. The change of plan — from undertaking a delivery voyage to trawling for fish — meant there was no one available to man the wheelhouse while the other crewman was working on deck, or to check for damage after the trawl doors had hit the hull. The change of plan, it says, introduced risks that were normally mitigated by having a third crewman. Any change of agreed plans or deviation from a standard operation should involve a step back and a reassessment of the risks. Had this been done, the decision to fish with reduced crew might not have been taken, and the vessel might not have sunk. 

Had the wheelhouse or internal spaces been checked periodically, the crew might have noticed the flooding or the sounding of the bilge alarms. Additional pumping capacity could then have been used to control the volume of water flooding the vessel. 

During the abandonment, the skipper ended up in the water without a PFD and was lucky not to have succumbed to the debilitating effects of cold water immersion. Had he not been quickly pulled into the liferaft by the owner, it is very possible that he would have drowned.  

The crew’s activation of the EPIRB led directly to their timely rescue — highlighting the importance of crew being familiar with how to use their vessel’s emergency equipment. 

Previous accidents

In the 10 years prior to Diamond D’s sinking, 185 flooding incidents aboard UK-registered fishing vessels were reported to the MAIB — with 69 resulting in the loss of the vessel.  

In March 2017, the 23m (75ft) trawler Ocean Way sank after suffering flooding in its aft compartment. The vessel’s starboard net had become stuck fast on the seabed and during attempts to free it the port trawl door hit the hull heavily and the boat began to flood as its pumps were unable to keep up with the volumes of water coming in. 

In January 2016, the 16m (52ft) potter Majestic sank as a result of unidentified flooding in its engine room. Although the bilge alarm sounded in the wheelhouse, the crew, working on deck, didn’t hear it. The flooding therefore continued unnoticed for more than an hour. 

Read the full Diamond D MAIB report

Meet Eric Holliday, chair of the IMarEST’s Global Fisheries Improvements Special Interest Group (SIG).


Dennis O’Neill is a freelance journalist specialising in maritime.