San Diego

A Coast Guard plane Monday continued to patrol the South Pacific in search of a San Diego family missing at sea.

Graham and Sheri Hughes, together with their sons, Alex, 21, and Ryan, 15, were sailing their 39-foot sloop Sea Dreamer on the return leg of a summer-long cruise, said Coast Guard Petty Officer Scott Hartvigsen from the Honolulu headquarters. The four were last seen July 29, when they left the Palmyra island chain 800 miles south of Hawaii, Hartvigsen said.

The Sea Dreamer failed to arrive in Hawaii on Aug. 16 as expected, and harbor checks in Hawaii and along the California coast turned up no trace of the boat, Hartvigsen said. Coast Guard planes searched unsuccessfully off the Southern California coast one day last week on the chance that the Hugheses had bypassed Hawaii, according to Chief Quartermaster Mark Vavra in San Diego.

Since Saturday, Coast Guard planes based in Hawaii have covered more than 300,000 square miles of the South Pacific in search of the family. The search will be suspended Thursday if the boat has not been found by then, Hartvigsen said.