The beautifully proportioned Corsair (IV) was the last of the four successive sea-going pleasure yachts owned by the American financier J. Pierpont Morgan. Designed for Morgan by Henry J. Gielow of New York, she was built in Maine at the Bath Iron Works in 1930 and classed as a twin-screw schooner. Registered at 2,181 tons gross (417 net), her steel hull measured 343 feet in length with a 42 foot beam, and she was powered by two General Electric turbo-electric engines producing 6,000bhp. Oil-fired, she could make 17 knots with ease and was widely regarded as one of the most perfect private yachts ever constructed. After ten years in service, mainly on the U.S. east coast and in the Caribbean, she was purchased for the Fleet Air Arm (Bermuda) in August 1940 and armed with 1-6pdr for patrol work. Sold out of the service in December 1948, she was overhauled and fitted out as a deluxe cruiser until wrecked off Acapulco, Mexico on 12th November 1949.