Due to the prevailing sea-breezes and long north-south ridge, Point Loma was a well-known gliding site during 1929-1935. William Hawley Bowlus the Superintendent of Construction on the Spirit of St. Louis and resident of Point Loma built the first American sailplane the Bowlus SP-1 and flew that aircraft along the west side of Point Loma to establish new American endurance records. Bowlus later used other refined designs to soar for over 9 hours near the Cabrillo National Monument, and one of Bowlus' students Jack C. Barstow soared over Point Loma for over 15 hours in 1930 to establish an unofficial world record for soaring endurance.