There was a surprisingly large amount of German U-boat activity off the US coast during those days. For example, in 1942 the oil tanker Virginia was anchored off the mouth of the Mississippi River in the Gulf of Mexico waiting to unload its cargo in New Orleans when three torpedoes from a German submarine, the U-507, hit the ship sinking it and killing 27 of its crew. The losses off the US East Coast were overwhelming in 1942, but the U-boats visited the area throughout the war and the entire US coastline suffered losses.
Curious, I tried to find details on his work, but could not find anything detailing how the military used positional probability to predict where the U-boats would appear. However, I did discover that Ernest Hemmingway, using his yacht Pilar, was involved in the search for U-boats and got sidetracked.
In 1942 and 1943 Hemingway was supplied with an assortment of machine guns, bazookas, and grenades by the US government enabling him to patrol the Caribbean. The marauding German submarines had roamed the Caribbean and sunk thousands of tons of Allied shipping. The plan was that Hemingway would lure a German U-boat close to Pilar then disable or sink it.
Hemingway had relocated to Cuba by 1939 where he purchased a villa outside Havana that he had previously rented and watched the world situation deteriorate. As a journalist Hemingway had covered the Spanish Civil War and even at times had exceeded his journalist role by bearing arms. In China in 1941 Hemingway had passed along information to an Army Intelligence team in Manila. In May, the Office of Naval Intelligence debriefed Hemingway and Secretary of the Treasury Henry Morgenthau heard his report.
After the US entered World War II Hemingway oversaw an ad hoc intelligence operation in Havana in 1942 that was praised by the American Ambassador. Offshore in the Caribbean Sea, U-boats were taking advantage of ripe pickings around such cities of Galveston, New Orleans and Houston, all major oil ports. Also, Aruba was the site of the biggest oil refinery in the world, a prime source of diesel, aviation fuel, kerosene, gasoline, and fuel oil, all of them vital to the Allied war effort.
On February 16, 1942, U-boats descended on Aruba, sinking tankers and shelling the refinery. Merchant ships also were targets. Sub attacks in 1942 at the height of the German Caribbean campaign sank 263 ships, exceeding total losses on the North Atlantic convoy route.
The first task was to reconnoiter and patrol the sea-lanes in the Caribbean near Cuba noting any surfaced U-boat and report it to the Navy. Listening to German radio traffic might also give him clues to German activities. He would also venture into isolated cays searching for German supplies. His yacht carried a specially made bomb with handles enabling two men to toss it into the U-boat’s conning tower, presumably after killing any German crew members who happened to be on deck.
In 1942, Hemingway took short reconnaissance cruises and in 1943, he established a base camp on Cayo Confites from which he made daily patrols.
The project was flop. They didn't spot any serious German activity and as for listening in on German radio traffic, that was a total bust... no one spoke fluent German. However, there was one time they actually spotted a U-boat 1,000 yards away and Hemingway shouted for the crew to go to their battle stations.
With Hemingway's young son Patrick armed with his .303 Lee-Enfield rifle and his 11-year old brother armed with his mother’s old gun, a Mannlicher Schoenauer rifle, the crew readied their bomb, but the Germans had no interest in a fishing boat and sped off. By the summer of 1943 the U-boat war in the Caribbean Sea was winding down and Hemingway was ordered home.
While reading about Hemingway's exploits I discovered his news report on a Florida hurricane titled Who Murdered the Vets? He was referring to the 1935 Labor Day Hurricane which Wikipedia described as “the strongest tropical cyclone of the 1935 Atlantic hurricane season, and the most intense hurricane to make landfall in the United States and the Atlantic Basin in recorded history.”
The hurricane lasted an incredible thirteen days, from August 29 to September 10. Hemingway wrote the article in the left-wing magazine New Masses. He asked numerous questions: Who sent nearly a thousand US war veterans to live in frame shacks on the Florida Keys in hurricane months? Why were they not evacuated before the hurricane struck? Who delayed sending the rescue train that washed away between mainland Florida and Key West? Who was responsible for their deaths?
After the hurricane Hemingway visited the Keys and found hundreds of bodies of civilians and veterans strewn everywhere, in the sea, in the mangroves, in the shelters, in trees, everywhere. In one camp, Hemingway found only eight survivors out of 187 veterans.
The storm was a category 5 that killed 408 people. People caught in the open were blasted with sand with such force that it tore away their clothing. On one key it stripped away every building and every tree. Among those who perished were 259 World War One veterans living in three Civilian Conservation Corps camps while they worked constructing the Overseas Highway. A train sent to rescue them arrived too late and many died on board when the train was swept off the tracks in a storm surge.
The storm had been first detected east of the central Bahamas on August 29th. By the time it turned to the middle of the Florida keys it had reached category 5. Any hurricane with winds of 157 mph or greater is a Category 5.
Recommended book: Hemingway's Cuba: Finding the Places and People That Influenced the Writer Look inside at Amazon