A reader brought this vessel to our attention. It is believed the Gaul sank on 8 February 1974.
Over the past 30 years a series of investigations have revealed two alternative theories on the Gaul's fate.
Some believe the trawler was captured by the Soviets because it had spies on board. In 2004 rumours emerged that a British submarine became entangled in the vessel's nets and dragged it underwater.
Successive governments have denied that the trawler was involved in espionage.
Following the subsequent showing of the documentary on UK television, the Deputy Prime Minister asked the Marine Accident Investigation Branch (MAIB) whether it was possible to determine the cause of sinking from this new material. The MAIB reviewed the available footage, and concluded that a more detailed examination of the wreck would be required to make any such judgement. The Deputy Prime Minister therefore directed the MAIB to conduct an underwater survey of the wreck and report on its findings.
Let us know if you have information about this fascinating case.