Specially ordered by Harold Vanderbilt to enter the famous 12 Metre races organized in British waters, Vim was Olin Stephens design no. 279, and very advanced for the period, based on the results of extensive tank tests and inspired by the previous design of the 6-metre Goose. Olin Stephens said "She was a real refinement on what I had done before." She is an 'outsize' Twelve as the later British ones (Trivia, Evaine and the 1939 built Tomahawk, Flica II, Ornsay and Jenetta) but with a more aggressive keel and fuller shape in the bow. Although she respected the minimum weight allowed by the class Rule, her mast was of duralumin in order to be stronger and stiffer than a mast of similar weight in other materials. She had the first two speeds coffee grinders to be mounted on a Twelve; the cockpit was smaller than usual and watertight. She had also one of the first or the first trim tab described as "a special device on her rudder - a special adaptation from aeroplane practice - by means of which the after edge of the rudder can be controlled from the cockpit independently of the rudder itself" This device was controlled by a hand wheel and internal worm gear which was located at the rudder head. boat until the 12-metre Australia II's winged keel of 1983. Above decks, Intrepid featured a very low boom, made possible by locating the winches below decks. The low boom caused an "end-plate effect",[clarification needed] making the mainsail more efficient.