St. David's Battery, on the cliffs of St. David's Head, was designated "Examination Battery" during the war, with its gunners ready to fire upon any vessel that attempted to move from the anchorage without authorisation.[11][12] Castle Harbour, which at this point remained on the civil register, was used to deliver the naval examiner and civil government pilot to arriving ships.[18] She was crewed by a mix of RN, RN Reserve and RN Volunteer Reserve, along with civil Merchant Navy and local Pilot Service personnel.[19][14][5]