The Coast Guard suspended its search Thursday for a sailboat reportly capsized by migrating whales off the coast of Encinitas Wednesday afternoon. The search was called off at 3:45 p.m., and no sailboats have been reported missing or overdue since that time, said Petty Officer First Class Pat Milton. The Coast Guard, however, is still investigating. The search began after the Coast Guard received a call from a woman who said she saw the boat overturn in waters one-quarter to one-half mile off Moonlight Beach State Park. County lifeguards were sent to the area but found no sign of an accident. The Coast Guard then sent two helicopters, an 82-foot cutter and a 41-foot rescue boat to join in the search. A Coast Guard helicopter continued the search at 7 a.m. Thursday, but found nothing. Only one person reported the incident, Milton said, adding that the woman said she only saw the craft out of the corner of her eye. The woman also said the craft had dark sails, and Milton said she may have seen a whale's fin.