The Sea Wolves (1981)

A German spy is passing on information about the location of Allied ships in the neutral harbor of Goa, India, with catastrophic results. Unable to undertake a full military operation in the Portuguese stronghold, English intelligence brings out of retirement a crew of geriatric ex-soldiers, veterans from World War I, using their age as cover. These old soldiers are asked to take to the seas and pull off an unlikely undercover mission.