Back a little over a week ago I had a "Shot of the Day" featuring the USS Pilotfish (SS-386) resting in 175 feet of water at the bottom of the Bikini Atoll. It as well as other ships were sunk as part of atomic bomb testing in July 1946 and are now dive destinations.
Operation Crossroads Baker Shot (Source: DOE)
I ran across some film of the Operation Crossroads Baker shot (National Geographic HERE or the DOE HERE) that resulted in the test target USS Pilotfish, moored at a depth of 168 feet and at a range of 363 yards from the point of the blast, in sinking. Only 21 of the 71 ships in the Able and Baker tests actually sank but all sustained damage. If not sunk during the tests the remaining ships were heavily contaminated with radiation and were either scuttled, sunk in gunnery exercises or scrapped.
The Baker shot was a 21-kiloton shallow water test detonated some ninety feet underwater and was the final weapon test conducted as part of the original Manhattan Project.