Curtis LeMay is best known for running Strategic Air Command in the 1950s and for serving as Air Force Chief of Staff in the 1960s. He's also known for leading the strategic bombing campaign against Japan at the end of World War II. But before all that, he pulled off an amazing maritime intercept.
Back in 1938, finding ships at sea was a lot harder than it is today. Even with today's technology, finding a ship that doesn't want to be found is difficult. Back then, they didn't have the advantages of radar-equipped maritime patrol planes, like the Lockheed P-3 Orion or Boeing P-8 Poseidon. Nope, all pilots had back then were binoculars to enhance the ol' Mk 1 eyeball.
Keep in mind those technical limitations as we talk about the feat LeMay pulled off in 1938. At the time, the Army Air Corps was in the midst of budget battles. The B-17 was in its infancy, and while the shooting hadn't started yet, there were some war clouds on the horizon. As hostilities loomed, inter-service rivalries flared, especially tensions over who would defend America's coast from the enemy.
Three Y1B-17s from the 2nd Bomb Group were selected to carry out an intercept of the Italian liner SS Rex. Aside from LeMay, the crews included Caleb Haynes, who would later become an air commander in the CBI Theater of World War II, and Robert Olds, the 2nd Bomb Group commander and father of legendary fighter pilot Robin Olds.
On May 12, 1938, the three Flying Fortresses took off. According to Air Force Magazine, LeMay had to adjust the plan for the intercept when he learned the SS Rex was further out than expected. That glitch allowed LeMay to demonstrate his amazing skills. The B-17s flew over 600 nautical miles off the coast of the United States, then dropped down almost right on top of the Italian liner.
Initially, the incident caused a fuss among the Navy, which still claims the Air Force cheated by tracking a homing signal operating from the Rex. However, it did lead President Franklin D. Roosevelt to become an advocate of long-range aviation. The B-17 would later become a legend over Europe and the Pacific, but much of it started with the intercept of the SS Rex.
The SS Rex, incidentally, would later be sunk after it was seized by the Nazis.