Seattle's floating restaurant Surfside 9 opened about 1960 on a converted ferry originally built in 1900 as the steamer City of Everett, a member of Puget Sound's Mosquito Fleet. Docked at the south end of Lake Union from about 1950, the restaurant was initially known as the Four Winds, famous as the headquarters of the Seafair Pirates.

This image of the Surfside 9 was taken one day after its sinking on July 22, 1966. Refloated six months later, it was amid plans to refurbish the vessel as a youth center that it sank again in May 1967. This time it remained partially submerged until lifted in 1972 by Mason Construction’s floating derrick, the Viking, and buried in an Everett landfill by the Army Corps of Engineers.

Caption information source: https://pauldorpat.com/2013/05/24/seattle-now-then-the-four-winds
Caption information also derived from captions written by Post-Intelligencer staff and attached to the back of the photograph.