From 1946 to 1958, the United States military conducted more than 20 nuclear bomb tests at Bikini Atoll, an idyllic tropical island in the South Pacific Ocean. During the first of these tests, conducted in July 1946, the military anchored nearly 100 warships and submarines within Bikini’s large lagoon to see how a nuclear blast would affect a naval fleet.

The first bomb, in test Able, was detonated in the air and caused a less than expected amount of damage to the fleet. But the second bomb, in test Baker, was suspended below a barge and detonated underwater.

The Baker test was far more destructive than the military had planned. The detonation left a crater on the seafloor roughly 800 meters (half a mile) wide and 10 meters (33 feet) deep. A colossal column of boiling, radioactive water poured over the target ships, tossing them about like toys in a bathtub.

Three major ships and several small aircraft were sunk within the first few days. The remainder of the fleet was so contaminated with radiation that only 9 of Baker’s original 84 ships were able to be scrapped – the rest were deliberately sunk.

University of Delaware professor Art Trembanis spent the summer of 2019 mapping the seafloor around Bikini to see if he could find evidence of these tests all these decades later. Art and his colleagues have so far discovered the craters from Baker and other tests have left permanent scars on the seafloor around the atoll.

In this episode, Art recounts the mesmerizing sequence of events triggered by the Baker detonation and explains how a tropical paradise became a battleship graveyard.

This episode was produced and mixed by Lauren Lipuma.