I heard that the McHale's Navy PT-73 was the chase boat for THE flight of the Spruce Goose.
Tim Conway just happened to be promoting an appearance yesterday, and said that a lot of the boat shots were on cardboard sets.
PT-694, a U.S.-built Vosper & Co. 73-foot (22 m) boat, was used in the television show McHale’s Navy, which featured the comic exploits of a fictional PT boat crew on “PT-73”. Until the mid-1990s, the boat was in private hands in Wilmington, California. The owner kept it seaworthy and ran it around from time to time. Unfortunately, while awaiting transit to San Francisco, the boat broke loose of its mooring in Santa Barbara, washed up on the beach, and was destroyed.