Atrysail (also known as aspencer[citation needed]) is a small triangular orgaff riggedsail hoisted in place of a largermainsail when winds are very high.[1] The trysail provides enough thrust to maintain control of the ship, e.g. to avoid ship damage, and to keep thebow to the wind. It is hoisted abaft (i.e., directly behind) themainmast (taking the place of the much largermainsail) or, on abrig, abaft theforemast.[2] A trysail is analogous to astorm jib.
In theRoyal Navy in the late nineteenth century, the term 'trysail' came to denote the main fore-and-aft sail on any mast. This included the mainsail of the 'great brig'HMSTemeraire, the largest fore-and-aft sail ever used by awarship. Naval trysails were usuallygaff-rigged and 'loose-footed', with aspar along thehead but noboom, and small auxiliary trysails continued in intermittent use into the 1920s forseakeeping andstation-keeping.[citation needed]