This was a great and highly enjoyable WWII submarine thriller for me. One of my favourite American war films made during wartime and easily the grittiest performance I have ever seen from Cary Grant. Some marvelous and exciting work with a great supporting cast of fine actors from that era that one just loved to see when going through films of that particular epoch. Very fine stuff to see here for the adventurous cinephiles out there who just assume Grant was a lazy comic actor who sleepwalked through his films.