It’s interesting how badly prepared we were at the beginning of the war. From 1942 to ‘43, Roosevelt called for volunteers to patrol off the Atlantic and Gulf coasts—as many as a thousand boats were assigned. We didn’t have enough Navy ships to cover these areas. The volunteers became known as the Hooligan Navy.

Hemingway was the only American civilian to patrol off of Cuba, where he was living at the time, and he had to get through a lot of red tape. But he was part of a huge surveillance network in place. You just never knew when the subs were going to come up. When ships in the Hooligan Navy spotted U-boats, they’d call for backup from the military.

But Hemingway had a different plan. If he spotted a U-boat, not only would he call for backup, he wanted to attack the sub himself. So he took some hand grenades and Thompson machine guns with him on his boat. Of course, trying to attack one of the subs was suicidal. If he had tried—if he’d gotten alongside the sub—U-boat captains would have sunk him. They sank anything they saw, even small fishing boats like his. It was suicide.

Hemingway wasn’t a war lover. He hated war. But he also said that once you’re in it, you have to win it. His experience hunting U-boats was a perfect metaphor for how he saw the universe: as something unpredictable, impersonal and lethal.

As told to Danielle Friedman.

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Terry Mort studied with Hemingway’s official biographer, Carlos Baker, at Princeton. He served as an officer in the Navy and spent three years on active duty, including a deployment to Vietnam and subsequent patrols of the Gulf of Mexico and the Caribbean. He is the author of three novels as well as a book on fly-fishing and has edited works by Mark Twain, Jack London and Zane Grey.