7 MAR--This Day in US Military History

1974 – The Civil War ironclad ship, Monitor, which sank in 1862, is discovered off the coast of Hatteras, North Carolina.

For more than a century, the Monitor’s resting place in the “Graveyard of the Atlantic” remained a mystery, despite numerous searches. In 1973, an interdisciplinary team of scientists led by John G. Newton of the Duke University Marine Laboratory located the Monitor while testing geological survey equipment for underwater archaeological survey and assessment.
Newton’s team determined the search area by replotting the track of the USS Rhode Island, a paddlewheel steamer that was towing the Monitor when she sank on New Year’s Eve, 1862. The Rhode Island’s logbook recorded events and times as the two ships rounded treacherous Diamond Shoals off Cape Hatteras, North Carolina. An 1857 coast survey chart helped refine the plotting of the search area. The scientists also developed sonar and visual configurations for the wreck with specific points of identification: the ship’s turret, armor belt, and nearly flat bottom.
On August 27, 1973, after identifying twenty-one possible contacts, side-searching sonar found a long, amorphous echo. The first pass of the television camera revealed iron plates; a virtually flat, unobstructed surface (the bottom of the hull); a thick waist (the armor belt); and a circular structure (the turret). With each successive series of camera passes, evidence mounted that the wreck was that of the Monitor, but it would take an intensive study of the visual evidence over the next five months to confirm it. A second visit to the site in April 1974 positively identified the Monitor, lying in approximately 230 feet of water about 16 miles south-southeast of Cape Hatteras.

https://thisdayinusmilhist.wordpress.com/2014/03/07/march-7/