I endorse the comments made a week ago on this site. The following additional comments may be of interest to viewers of this film (released on DVD by the Imperial War Museum on 2005).
The opening frames of the film show Lieutenant Commander David Gregory, the Commanding Officer of the submarine HMS Tyrant (actually HMS Tribune - N76) returning from leave. The Submarine Depot Ship is HMS Forth, with her submarines alongside to port and starboard, in the Holy Loch, near Dunoon in the Firth of Clyde (some 25 miles west of Glasgow). The Holy Loch later became the US Navy's submarine base.
The boat's honours board - seen on the fin of HMS Tyrant as the submariners remark on the "skipper's" return - is probably genuine but a little different to those formally approved for use by HMS Tribune in the 1950s. The First Lieutenant or 'Number One' - second-in-command - of HMS Tyrant is a Lieutenant of the Royal Naval Reserve (RNR).
As HMS Tyrant sails from the Depot Ship, while saluting Captain SM, you may see the flag of the Netherlands - clearly a Dutch submarine was also alongside (perhaps HNLMS Zeehond?).
The two-funnel destroyer that escorts the two submarines out to sea - called HMS "Cutty Sark" in the film - is a tough one to identify. Perhaps she is an S Class destroyer built in World War I - an old destroyer would make sense for this duty as it's not a 'front line' role. Eight S Class remained in service by 1943.
For viewers not familiar with naval jargon, "Pilot" means the Navigating Officer, "Subby" means a Sub-Lieutenant and "Chief" means the Marine Engineering Officer. The film is sometimes dubbed "In Which We Submerge"!
The T Class submarines were built from 1937 to 1944 and none is preserved. The smaller U and V Class were built during the same years.
The T Class was followed by the broadly similar A Class submarines, the first of which was launched in early 1945, but most were cancelled owing to the end of hostilities. A few were completed and formed the backbone of the RN Submarine Service in the post-war years.
One of this Class, HMS Alliance (1945), is preserved at the Royal Navy Submarine Museum in Gosport, Hampshire. A visit to her will give you a real feel a typical WW2 submarine and you will be able to see for yourself just how good was the Pinewood Studios full-size model of the interior of HMS Tyrant! (HMS Alliance was still in service in 1972, as she was on duty for the Britannia Royal Naval College, Dartmouth, taking Midshipmen like me for a dive in Torbay - the pervasive smell of diesel oil put me off volunteering for service in submarines!).
Summary: Great film > Buy the DVD > Visit the RN Submarine Museum!
