The Battle of the Atlantic would eventually turn decisively in the Allies’ favor in May 1943, with the introduction of improved convoy protection, centimetric radar that allowed aircraft to detect surfaced submarines at night, and the cracking of Enigma codes that allowed Allied forces to route convoys around known U-boat patrol zones. By that point, Poon Lim had already been rescued. He spent his survival ordeal at the tail end of the most dangerous period of the Atlantic campaign.
## The Merchant Seaman’s War, Invisible
One of the persistent realities of how the Second World War is remembered is the relative invisibility of the merchant marine within the dominant narrative. The sailors who held the supply lines of the Allied war effort — who carried the oil, the food, the ammunition, the vehicles, the raw materials without which armies could not move and civilian populations could not be sustained — did not receive the attention or the formal recognition that combatant military personnel did, during the war or in the decades afterward.
The numbers tell the story that the popular narrative often omits. The British merchant navy lost approximately 36,000 men during the Second World War, out of a service of roughly 185,000. This is a death rate of approximately 19 percent — comparable to or exceeding the casualty rates of several branches of the armed forces. Merchant seamen were not conscripted; they served as civilians, under contract, without the legal protections and benefits that military service conferred. They were not awarded campaign medals during the war (this was not rectified until 2013, when the UK government finally awarded a campaign medal to surviving merchant navy veterans). Their deaths were recorded differently, grieved differently, and remembered differently.