The crew members and boat debris were found near the Coronado Islands in Mexico. The crew was participating in the 125-mile Newport to Ensenada International Yacht Race when something went wrong.
They were aboard a 37-foot sailboat named Aegean. Its home port is Redondo Beach.
The Coast Guard has not yet released the names of the victims. However a relative of the boat's owner, Theofanis Mavromatis, told Eyewitness News he was on board.
The Coast Guard is investigating what may have happened to the boat and it is unclear if the yacht was in a wreck. Coast Guard officials say conditions were fine for sailing, with good visibility and manageable ocean swells.
The Associated Press contributed to this report.