Lyndonia, built 1920, was the second steam-yacht bearing the name[
and the third yacht built for publisher Cyrus H.K. Curtis by the then Consolidated Shipbuilding Company of Morris Heights, New York. The name is taken from the historic name of his estate, Lyndon, in Wyncote, Pennsylvania.
After Curtis' death in 1933 the yacht was purchased by Pan American Airways, converted to a floating hotel for use in the south Pacific and renamed Southern Seas in a shuttle service from Nouméa to Australia. At the outbreak of World War II the vessel was taken over by the U.S. Army for use as a passenger and cargo ship until grounded on a New Caledonian reef. The ship was salvaged by the U.S. Navy, repaired in New Zealand, commissioned 23 December 1942 as USS Southern Seas and designated as a Patrol Yacht (PY-32).