The strait was surprisingly elusive for early European explorers, presumably due to persistent summer fog. The strait is not recorded in the voyages of Juan Rodríguez Cabrillo nor Francis Drake, both of whom may have explored the nearby coast in the 16th century in search of the fabled Northwest Passage. The strait is also unrecorded in observations by Spanish galleons returning from the Philippines that laid up in nearby Drakes Bay to the north. These galleons rarely passed east of the Farallon Islands ( west of the Golden Gate), for fear of the possibility of rocks between the islands and the mainland.