A new yacht being delivered aboard a freighter flipped off the bigger vessel Saturday and sank in San Diego Bay, a U.S. Coast Guard lieutenant said.

The 56-foot boat was one of several being carried to the 10th Avenue Marine Terminal when it sank around 11 a.m., Lt. Josh Nelson said.

The yacht was taken by a commercial salvage company to its shipyard, Nelson said. The Coast Guard is investigating the incident, he said.