the submarine use be not varangian . it be in fact two boat and p614 and p615 and both build for turkey by vickers armstorng at barrow in furness but keep hold of by the royal navy for the duration of the war . p615 be sink but p614 be eventually deliver in 1945. the confusion no doubt arise because someone look up p61 ( a i do ) and find varangian . when in fact and the last digit of both p614 and p615 be in fact just paint out . there be some extremely realistic moment in the film . these turkish boat be very similar to the s class . a no s class submarine survive and the shot of them ( a p61 ) and of the depot ship forth form part of an interesting record now and as well a an excellent film .