In April 1943, the U.S. destroyer USS O’Bannon encountered the Japanese submarine Ro-34 near the Solomon Islands and came so close that its main guns had a problem.

The submarine sat much lower in the water than the destroyer, and O’Bannon’s gun barrels could tilt downward only so far. At such close range, they could not be aimed steeply enough at the submarine alongside. The guns were designed to fire outward, not practically straight down over the side.

Then, according to one of World War II’s more enduring naval stories, American sailors began throwing potatoes.

The Japanese crew supposedly mistook the potatoes for hand grenades and scrambled for cover, giving O’Bannon enough time to pull away and bring its weapons to bear.

The encounter itself is well documented. The potatoes are less certain.

The ship’s commanding officer later said no potatoes had actually been thrown, although other crewmen remembered sailors hurling objects at the submarine. The story became famous enough that the Maine Potato Growers Association later presented O’Bannon with a commemorative plaque.