skysail—The square sail sometimes set above the royal. It carries also the name of the mast on which it is set, as main skysail.
sloop—Sailing vessel with one mast, like a cutter but having a jib stay, which a cutter has not. A jib stay is a support leading from the mast to the end of the bowsprit on which a jib is set.
smack—The name given indiscriminately to any sort of fishing vessel using sails.
snow—A vessel formerly common. It differs slightly from a barque. It has two masts similar to the main and foremasts of a ship, and close behind the mainmast is a trysail mast. This vessel is about extinct.
sounding—Determining the depth of water and the kind of bottom with the lead and line.
southwester—(pronounced sou-wester)—A waterproof hat with the widest part of the brim at the back.
spanker—The fore-and-aft sail set on the mizzenmast of a square-rigged ship. Sometimes called the driver.
spar—A spar is any one of the timber members of a vessel’s gear.
spinnaker—A racing sail of immense spread reaching from the topmast head to the end of a spinnaker boom which is a spar set out to take it. Sometimes it is possible for the same sail to be made to perform the services of a balloon jib, by carrying the spinnaker boom out until the end to which the sail is made fast is beside the end of the bowsprit.
splice—(Verb) To join rope by interweaving the strands. (Noun) The joint made in rope by interweaving the strands.