Maurice Spurgeon joined the crew on the 28th at Tromsø and Gaul arrived at the fishing grounds off the north coast of Norway the following day.
[3][9][10] The original Formal Investigation in 1974 concluded that the most likely reason for her loss was that she was overwhelmed by a succession of very large waves in heavy seas and capsized.
[11][12][13] The preliminary investigation had also found deficiencies in the maintenance of chutes, doors and hatches on Gaul's sister ship Kurd, but the relevance of this fact was downplayed at the formal inquiry.
Gaul was one of the most modern ships in the UK fishing fleet — she was only 18 months old — and relatives of the crew were reluctant to accept the investigation findings.
[4] This prompted UK Deputy Prime Minister (and Hull MP) John Prescott to ask the Marine Accident Investigation Branch of the Department for Transport to carry out extensive surveys of the wreck, which it did in 1998 and 2002.
Additionally, the inner cover to the duff chute appeared to be secured open and the ship's steering gear (a steerable kort nozzle) was found to show between 10° and 15° of port helm.
[16] On 17 December 2004 the RFI concluded that these open chutes, doors and hatches had compromised the ship's watertight integrity and, combined with a following (and as already noted) heavy sea led to flooding on the factory deck.
The RFI also postulated that an attempted emergency manoeuvre by the Gaul's officer of the watch (a perfectly logical move to try to turn 'into the sea') caused 100 tonnes of floodwater to surge across to the starboard side of the ship leading to capsize and a catastrophic loss of stability.
Further flooding then took place through open doors, chutes and hatches until the Gaul lost her reserves of buoyancy, she then sank very rapidly, stern first.
Regarding espionage the report did include, verbatim, the following submission from Commander Clark RN: "Skippers, radio officers and Mates of trawlers were involved in the low level observation and photography of Soviet vessels and aircraft and passive listening.