“Like its predecessor tonight (also directed by Frend), San Demetrio--London is based on an actual incident, and despite being almost wholly set at sea while being almost wholly shot in a studio, manages (helped by a cast of non-stars) to be both exciting and virtually a documentary. Extremely well received by the British press, it was not the success it deserved to be, mainly because Warners' Action in the North Atlantic...(with) Humphrey Bogart, had come out just a few months earlier. An extremely interesting film, one of Britain's wartime best, and with a far subtler concentration on character and motivation than was usual in this kind of film.” William K. Everson