A tall ship is not a strictly defined type of sailing vessel. Most of us use the term to mean a large traditionally rigged sailing vessel, whether or not it is technically a "ship". The United States Coast Guard's training ship Eagle, for example, is technically a "barque". A tall ship can also be a schooner, brigantine, barquentine, brig, ketch, sloop, or a full-rigged ship depending on the number of masts and the cut of the sails.

All square-rigged vessels and all other vessels over 40m (131 feet) length overall (LOA).

Traditional-rigged vessels with a LOA of less than 40m (131 feet) and with a waterline length (LWL) of at least 9.14m (30 feet).

Modern-rigged vessels with a LOA of less than 40m (131 feet) and with a LWL of at least 9.14m (30 feet), not carrying spinnaker-like sails.

Modern-rigged vessels with a LOA of less than 40m (131 feet) and with a LWL of at least 9.14m (30 feet), carrying spinnaker-like sails.