<Table> <Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (March 2018) (Learn how and when to remove this template message) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (March 2018) (Learn how and when to remove this template message) </Td> </Tr> <P> A PT boat (short for Patrol Torpedo boat) was a torpedo - armed fast attack craft used by the United States Navy in World War II . It was small, fast, and inexpensive to build, valued for its maneuverability and speed but hampered at the beginning of the war by ineffective torpedoes, limited armament, and comparatively fragile construction that limited some of the variants to coastal waters . </P> <P> The PT boat was very different from the first generation of torpedo boat, which had been developed at the end of the 19th century and featured a displacement hull form . These first generation torpedo boats rode low in the water, displaced up to 300 tons, and had a top speed of 25 to 27 kn (29 to 31 mph; 46 to 50 km / h). During World War I Italy, the US and UK developed the first high - performance motor torpedo boats (often with top speeds over 40 kn (46 mph; 74 km / h)) and corresponding torpedo tactics, but these projects were all quickly disbanded with the Armistice . World War II PT boats continued to exploit some of the advances in planing hull design borrowed from offshore powerboat racing and were able to grow in size due to advancements in engine technology . </P>

What does the pt stand for in pt boat