A 37-foot racing yacht was reduced to debris that looked “like it had gone through a blender,” a searcher said Sunday after the boat apparently collided with a larger vessel, killing three sailors and leaving a fourth missing.

The U.S. Coast Guard, the Mexican navy and civilian vessels scoured the waters off the shore of both countries for the missing sailor from the Aegean, which was taking part in a 124-mile race that began Friday from Newport Beach, Calif., to Ensenada, Mexico. The sailboat, carrying a crew of four, was reported missing Saturday.

Race officials said they had few explanations for what may have happened to the Aegean other than it must have collided with a ship like a freighter or tanker that did not see the smaller vessel.

The Coast Guard said conditions were fine for sailing, with good visibility and moderate ocean swells of 6 to 8 feet.

The San Diego Medical Examiner’s office identified two sailors as William Reed Johnson Jr., 57, of Torrance, Calif., and Joseph Lester Stewart, 64, of Bradenton, Fla. The name of the third sailor whose body was pulled from the waters Saturday has been withheld pending notification of relatives.