A trawler almost capsized when a Royal Navy submarine from Faslane became tangled in its net and dragged it backwards through the water.

The nuclear-powered sub was sailing out of Faslane on the Clyde in April 2015 when it snagged the Karen's fishing gear between Ardglass and the Isle of Man.

The Irish trawler, which had four crew aboard, was pulled backwards and under the water for 30 seconds before the net snapped.

Investigators have now concluded the accident was a result of poor route planning by the submarine's command team and said the lives of the trawler's crew had been put at risk.

They noted it was "almost inevitable the Karen would have sunk" had its net not broken.

The Karen's skipper, captain Paul Murphy, said: "The Navy said that they have put in place 12 new recommendations [but] we are not privy to that so the Navy has to meet with us, explain their decisions on it and I think give us some more information on the actual incident [to] give the fishing industry a bit more confidence back in them.

"If they come clean about exactly what happened, why it happened, where their downfalls were, then we can understand it better and then get on with it but they have to come and talk to us."

A Marine Accident Investigation Branch report published on Thursday said: "Eighteen months ago, the actions of the command team of a Royal Navy submarine placed the lives of the crew of the trawler Karen in danger.

"Regrettably, the reluctance of the Royal Navy to fully engage in the subsequent investigation resulted in this report taking significantly longer to deliver than would normally be the case.

"The accident happened because of insufficient passage planning by the submarine's command team and their failure to follow guidance on fishing vessel avoidance.

"Had its trawl warps not parted, it is almost inevitable that Karen would have capsized and sunk. The collision also presented a very significant risk to the submarine."

The investigators added: "The Royal Navy's code of practice for fishing vessel avoidance was created after the loss of the trawler Antares and its crew in 1990.

"However, it is apparent that lessons learnt after the Antares accident have been lost.

"As a result, it is now important that the Royal Navy reviews its procedures and training for the safe conduct of dived submarine operations in the same vicinity as vessels engaged in fishing.

"By its actions, the Royal Navy also needs to rebuild trust with the fishing industry."

A Royal Navy spokesman said the navy "remains sorry" for the incident and the delay in admitting its involvement.

They added: "We have expressed our regret and remain sorry for the incident and delay in confirming our involvement.

"We've revised our procedures to reduce the risk that such an incident could happen again. We're reviewing the report's recommendations and continue to work closely with the maritime community to maximise safety."