Unfortunately not much information about a particular PT boat exists. The P 520 is an 85ft Army airforce crash boat built in 1944. Initially only two sizes of crash boat exist the 104ft version, and the 63ft version. The US Army quartermaster corps asked for a boat smaller than the 104ft but larger than the 63ft with transoceanic capability, hence the creation of the 85ft boats with an initial production run of 140. Crash boats were used for search and rescue of downed pilots from WWII through the Cold War. Boats like the 520 would typically operate for about 3-4 days at sea, but it wasn’t uncommon during Vietnam for crews to be aboard for 2 months with at sea resupplies. The 520 was sold as surplus in 1947, and was stored in Long Beach California for eventual use as a museum. Thought to be in excellent condition Bud Tretter begun inspecting the 520 realizing she needed a lot of work including new engines, and replanking of the wooden hull he began the process, and over decades on his own dime reapired the boat fully. Bud ending up passing away in 2012, and his son Jerry continued to store the boat until his passing in January of 2020. Jerries’ widow than donated the boat to the Louisville Naval Museum, where she will be used as a living museum rather than a static display.