The Flying 15 was designed by Uffa Fox in 1947 and the first hulls were built at his Cowes based boatyard. Uffa recounts in his 1959 book, "Sailing Boats" that Jimmy Damant, a Commodore of the Island SC and one of the earliest owners of the International 14, had often encouraged him to; "Design a boat like the 14-footer, but at least 18ft long, that will not capsize. Then you would have a sensible, safe boat, that was fun to sail as well, for the rough and tumble of tidal waters like the Solent."
Uffa eventually drew-up a hull twenty foot overall, fifteen foot on the waterline and drawing nine inches without the keel. The steeply raked keel adds 2ft 6inches to the draft, the rake helping to remove any weed. The original construction was for a 1/8" thick diagonal inner skin and 3/16" fore and aft, honduras mahogany outer skin over 3/8" x 1/4" ribs at 2" centres. The deck was 3/16" marine plywood. The original design weight was 285lb for the hull with a 400 lb keel. Driving this was a sail plan and mast height exactly as for the International 14 of that period.