Divers located the body of the missing boater, Elliott Edgars Hamilton Rivers, 19, at about 7:30 p.m. Thursday after 11 hours of searching, said Columbia County Emergency Services Director Pam Tucker.
Dive teams from the Richmond County and Columbia County Emergency Management agencies conducted the search.
Mr. Rivers was boating with friends about 4 p.m. Wednesday when he was thrown overboard as the boat made a sharp turn near the area of Lake Springs Park and Tradewinds Marina near Thurmond Dam, Mrs. Tucker said.
Authorities narrowed their search to an area 100 yards long by 100 yards wide and 35 to 60 feet deep Thursday, she said.
Authorities discovered damage to the propeller of the boat that Mr. Rivers was in, Mrs. Tucker said.
Though friends described Mr. Rivers as a good swimmer, it is possible he was struck by the propeller after being thrown from the boat, she said.
Mr. Rivers graduated from Westminster Schools of Augusta in 2006 and had been an active member of First Presbyterian Church of Augusta, according to a statement released by the church's pastor, who also is chairman of the Board of Trustees at Westminster.
"As a covenant child of First Presbyterian Church and an alumnus of Westminster Schools of Augusta, Elliott was an integral part of our faith community," Dr. George Robertson said in an e-mail.
He also played soccer for Westminster and was honorable mention on The Augusta Chronicle 2006 All-Area Soccer Team. Mr. Rivers enrolled at Georgia Southern University after high school.
He is the son of Cary and Madeline Rivers, and has five brothers: Chris, Todd, Oliver, Charles and Jesse.
Columbia County Bureau Chief Preston Sparks and reporter Rob Pavey contributed to this report.
Reach J. Scott Trubey at 706-868-1222, ext. 109, or firstname.lastname@example.org.