List of shipwrecks in 1921

The cargo ship last reported from the Atlantic Ocean 250 nautical miles (460 km) north of Jupiter Inlet, Florida.

[30] After Hewitt failed to arrive in Boston on its expected due date of 29 January, Union Sulphur sent the ship's wireless call (K I L) through Atlantic coastal stations, and notified the United States Navy.

US Coast Guard officials in Atlantic City reported hearing an explosion and seeing a flash approximately 20 miles (32 km) offshore on the night of 3 February 1921, and connected this event with the Hewitt.

[31] The Wiesbaden-class light cruiser (formerly  Imperial German Navy) was sunk as a target ship by United States Army Air Service and United States Navy bombers in the Atlantic Ocean off Cape Henry, Virginia.

The Helgoland-class battleship (ex- Imperial German Navy) was sunk as a target by United States Army Air Service aircraft in the Atlantic Ocean off Cape Hatteras, North Carolina.

USS Coast Defense Battleship No. 2 sinking
SS Hewitt
Stern view of the wreck of Conestoga in 2014.
USS Frankfurt
USS Ostfriesland sinking
Sonar image of the wreck of Helvetia , June 10, 2022.
USS Alabama struck by a bomb on 23 September 1921 while in use as a target ship .
DeLong
USS S-48