Ringtail
Flown outside the back edge of the mainsail, and flown downwind. Only used by Historic 18-footers. It is hoisted to the top of the gaff, or the head of the mainsail, by a halyard that goes up in front of the mainsail; rolled out under the boom and pulled out along the boom until it protrudes half its width beyond the mainsail. Not all boats use a ringtail, and it cannot be carried in heavy weather.