Shotley is a small town in Suffolk which has a shore training station of the Royal Navy.
Commander Ted Walker came home from Hong Kong to be stationed here (and promoted to the rank of Captain) in 1931. Daddy had been looking forward to a week of freedom before settling down to work at Shotley. Titty says He's going to be stationed at Shotley (SW1). When Daddy joins them at Flushing he asks an old friend, Captain Curtledge at Shotley, to sent a telegram from the Swallows to Mother as the telegram mustn't come from Holland or your Mother'll be throwing fits (SW22).