German submarines of WW2 didn't carry searchlights or machine guns of the type shown.
Lanser's room on the sub is far too large and clean. U-boats had very little space on them, with even the Captain afforded only a tiny amount of room, usually just enough to sit at a desk.
The captain of SS Queen of Glasgow is wearing the ribbons of the Africa Star, the Italy Star, and the 1939-45 War Medal in 1942. None of these medals had been instituted at that time.
This is a British ship; however, the closeup of the clock features an American-made Seth Thomas clock. The clock is "period correct" for WWII American ships, just unlikely to be on British ships as the British have their own established clock makers.
Lt. Mueller's German accent drifts in and out constantly.