"He’s just got to be in Dartmouth for a week."

Britannia Royal Naval College
Creative Commons Attribution Share AlikeBritannia Royal Naval College - Credit: Herbythyme, Wikimedia
The Royal Naval College, Dartmouth, now called the Britannia Royal Naval College is where Royal Navy officers receive their initial training.

Terence would not have been able to instruct there much longer.  In September 1942, the college was bombed, and officer training was then conducted at Eaton Hall in Cheshire until 1946.