Peeling Potatoes. Royal Navy rations varied during the war - At the begining, peacetime menus containing New Zealand lamb, Australian beef, and Irish potatoes and fresh Caribbean vegetables. Good food continued until U-boats began to constrict the food getting to the United Kingdom. After the Fall of France until the Germans began ramping up for the Invasion of Russia, beef and lamb were not always available. Lend-Lease also brought American food, including spam, which was supplied to all Allies on all fronts, creating a huge popularity for the canned meat. Personally I think it was just popular because any food was welcomed, even if it was packed in grease and smelled funny. Almost no fresh vegetables were available on US or Royal Navy ships for the duration, and many British ships (and the civilian population) lacked fresh vegetables until the late forties. Each seaman in the British Navy was issued a daily ration of grog - watered down rum. Seamen who didn't get their daily ration of rum were sometimes quite angry about it.
In Axis navies, the food was much, much worse. The Japanese sailors who dared to venture forth in 1945 would have to make due with half rations or less than a comparable US Navy ship. American submarine rations were the best in any navy.