GREENVILLE, SOUTH CAROLINA—The remains of the Planter, a ship commandeered in Charleston Harbor by a 23-year-old enslaved man named Robert Smalls, may have been found buried in ten feet of silt with scanning sonar and a magnetometer. Smalls and other African-American crewmembers took control of the transport steamer, picked up Smalls’ wife and children, and headed to the Union blockade in 1862. He surrendered the vessel, which was transformed into a Union gunboat with Smalls as its captain. The Planter eventually sank off Cape Romain in 1876. “We have probed down. We know there’s wood there and we know there’s metal there, but we don’t know absolutely whether it is or is not the Planter,” Gordon Watts of Tidewater Atlantic Research Inc. told Greenville Online. Smalls went on to serve five terms in Congress. The site will be monitored and protected.