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Commercial Fishing



Galwad-Y-Mor, subsea explosion, near Cromer, Norfolk. MAIB Report on the investigation of subsea explosion, resulting in crew injuries and damage to the crab potting vessel Galwad-Y-Mor (BRD 116), 22 nautical miles north of Cromer, Norfolk, on the 15 December 2020


At 11.22 on 15 December 2020, the 15m crab potting vessel Galwad-Y-Mor was hauling pots in the North Sea approximately 22 miles north-east of Cromer. The crabbing gear disturbed a 250kg unexploded WWII bomb, which detonated on the seabed below the vessel.

The ensuing explosion caused a shock wave that threw Galwad-Y-Mor about, resulting in significant injuries to five of the seven crew and major damage to the vessel’s hull and machinery. Despite their injuries, Galwad-Y-Mor’s crew were able to send a distress message, launch the liferaft, and board rescue boats that had been dispatched by a nearby offshore support vessel. The injured crew were transferred to hospital by helicopter and RNLI lifeboat. They were treated for head, back and knee injuries. Galwad Y Mor was successfully salvaged and has been rebuilt.

The key safety issues identified were:

  • Unexploded ordnance (UXO) can be highly volatile even after many years of being submersed. In the event of encountering a UXO, seafarers are advised to follow the recommendations in MGN 323 (M+F) Explosives Picked Up At Sea.
  • Galwad-Y-Mor’s crew could not have anticipated the fouling of a bomb in the potting string and the resulting explosion; their training, experience and emergency preparedness improved their chances of survival.

Photo credit: Andrew Oliver