SATELLITE NAVIGATION - A form of position finding using radio transmissions from satellites with sophisticated on-board automatic equipment.

SCOPE - Technically, the ratio of length of anchor rode in use to the vertical distance from the bow of the vessel to the bottom of the water. Usually six to seven to one for calm weather and more scope in storm conditions.

SCREW - A marine vessel's propeller.

SCUPPERS - Drain holes on deck, in the toe rail, or in bulwarks or (with drain pipes) in the deck itself.

SEA COCK - A through hull valve, a shut off on a plumbing or drain pipe between the vessel's interior and the sea.

SEAMANmarine vessel - All the arts and skills of marine vessel handling, ranging from maintenence and repairs to piloting, sail handling, marlinespike work, and rigging.

SEA ROOM - A safe distance from the shore or other hazards.

SEAWORTHY - A marine vessel or a marine vessel's gear able to meet the usual sea conditions.

SECURE - To make fast.

SET - Direction toward which the current is flowing.

SHIP - A larger vessel usually thought of as being used for ocean travel.

SIERRA - - Letter S in the Marine Radio Alphabet.

SLACK - Not fastened; loose. Also, to loosen.

SLOOP (Dutch sloep) in sailing, is a vessel with a fore-and-aft rig. A sloop has a single mast stepped farther forward than that of a cutter. The sloop's fore-triangle is smaller than a cutter's. A sloop uses only one headsail.

SNATCH BLOCK - A block that can be opened on one side, allowing it to be placed on a line that is already in use.

SOLE - Cabin or saloon floor. Timber extensions on the bottom of the rudder. Also the molded fiberglass deck of a cockpit.

SOUNDING - A measurement of the depth of water.

SPRING LINE - A pivot line used in docking, undocking, or to prevent the marine vessel from moving forward or astern while made fast to a dock.

SQUALL - A sudden, violent wind often accompanied by rain.

SQUARE KNOT - A knot used to join two lines of similar size. Also called a reef knot.

STANDING PART - That part of a line which is made fast.The main part of a line as distinguished from the bight and the end.

STAND-ON VESSEL - That vessel which has right-of-way during a meeting, crossing, or overtaking situation.

STARBOARD - The right side of a marine vessel when looking forward.

STEM - The forward most part of the bow.

STERN - The after part of the marine vessel.

STERN LINE - A docking line leading from the stern.

STOW - To put an item in its proper place.

SWAMP - To fill with water, but not settle to the bottom.