Prince William is one of two tall ships used by the Tall Ships Youth Trust (formerly the Sail Training Association). This British charity aims to promote self-confidence, responsibility, teamwork and similar qualities in young people through sailing Prince William and Stavros S Niarchos. The former Sail Training Association was previously equipped with two schooners, Malcolm Miller and Sir Winston Churchill, but these were seen as too old for further use (in terms of accommodation and so on, since the rigs are traditional) and were replaced. As of November 2007 the Prince William was laid up as the trust awaits the sale of one of the two brigs.
The TSYT's ships are two-masted brigs, with the rig designed by Michael Willoughby (his description of the design). The hulls were built in Germany as cruise ships for the West Indies, designed to carry masts and sails and use them from time to time, but not to be serious sailing vessels. This project was cancelled and the part-finished hulls were bought in 1997 by the TSYT. They were then modified by Appledore Shipbuilders to take the strains of a full sailing rig and to improve their sailing properties, including the addition of a new deeper keel holding fifty tons of ballast.
Prince William's rig is designed according to traditional rules, occasionally modified slightly with trainees in mind. The foremast is slightly shorter than the main mast, but they are otherwise identical. Each consists of a steel lower mast and topmast and timber topgallant and royal mast. Spars are steel on the lower and topmasts (course, lower topsail and upper topsail yards) and timber above this (topgallant and royal yards). Access to the tops is by a vertical "jacob's ladder" down to the ratlines, rather than inverted futtock shrouds. There is a gold sovereign placed under the foremast where it meets the keel, a tradition supposed to give the ship luck.