The German forces had surrounded British and French troops and were advancing against them. The Allies literally had their backs to the ocean. More than 400,000 men were trapped with no way out. The British Navy was called in to try to rescue some of the troops, but with Hitler’s planes dropping bombs from sky and Nazi tanks rolling forward, it looked desperate. Worse, French sea town of Dunkirk was a shallow port, so shallow the large navy vessels could not get close to shore. There was only one choice—to use “Operation Dynamo.” The British Navy might not have shallow water boats, but British people did. As an island nation laced with rivers, the British people owned many pleasure boats, private yachts, commercial fishing boats, and flat-bottomed ferries. The soldiers still had to wade out to waist-deep water to get on the boats and then the ships took the soldiers out to the large warships waiting in the ocean.