At Sea Glossary - S
safety harness
A device worn around a person's body that can be attached tolines to help prevent the person from becoming separated from the boat.
sail
1) A large piece of fabric designed to be hoisted on the spars of asailboat in such a manner as to catch the wind and propel the boat.
2) The act of using the wind to propel a sailboat.
sailboat
A boat which uses the wind as its primary means of propulsion.
sailcloth
A fabric, usually synthetic, used to make sails.
sail shape
The shape of a sail, with regard to its efficiency. In high winds, a sail would probably be flatter, in low winds rounder. Other circumstances can cause a sail to twist. Controls such as theouthaul, halyards, sheets and the bend of the main mast all can affect sail shape.
sail trim
The position of the sails relative to the wind and desired point of sail. Sails that are not trimmed properly may not operate efficiently. Visible signs of trim are excessive heeling and the flow of air past telltales.
sampson post
A strong post used to attach lines for towing or mooring.
sand bar
An area in shallow water where wave or current action has created a small, long hill of sand. Since they are created by water movement, they can move and may not be shown on charts.
satellite navigation
Navigation using information transmitted from satellites.
scale
Climb.
schooner
A sailboat with two or more masts. The aft mast is the same size as or larger than the forward one(s).
scope
The ratio between the length of the anchor rode and the depth of the anchor. A scope of 7:1 is usually used, depending on theholding ground. Too little scope can cause the anchor to drag.
screw
A propeller.
scud
To run before the wind in a storm.
scull
A method of moving a boat by using a single oar at the stern.
scupper
An opening through the toe rail or gunwale to allow water to drain back into the sea.
scuttle
To sink a boat.
sea
1) A body of salt water. A very large body of fresh water.
2) Any body of salt water when talking about its condition or describing the water around a boat. Heavy seas for example.
sea anchor
A device designed to bring a boat to a near stop in heavy weather. Typically, a sea anchor is set off the bow of a boat so that the bow points into the wind and rough waves.
sea buoy
The last buoy as a boat heads to sea.
sea level
The average level of the oceans, used when finding water depths or land elevations.
seagoing
A vessel designed to be able to cross oceans.
seamanship
The ability of a person to motor or sail a vessel, including all aspects of its operation.
secure
To make fast. To stow an object or tie it in place.
securite
A message transmitted by radio to warn of impending storms, navigational hazards and other potential problems that are not an immediate threat to life or property. Less serious than mayday andpan pan messages.
seizing
Tying two lines, or a spar and a line, together by using a small line.
set
1) To put an object in place.
2) The manner in which an object is in place.
3) The direction that a current is moving.
severe tropical cyclone
An intense tropical weather system with a well-defined circulation and maximum sustained winds of 74 miles per hour (64 knots or higher in the Southwest Pacific Ocean (west of 160° east longitude) or in the Southeast Indian Ocean (east of 90° east longitude). In other parts of the world, they are known ashurricanes, typhoons and tropical cyclones.
sextant
A navigational instrument used to determine the vertical position of an object such as the sun, moon or stars. Used with celestial navigation.
shackle
A metal U-shaped connector that attaches to other fittings with the use of a pin that is inserted through the arms of the U.
shake out
To remove a reef from a sail.
shank
The long bar part of an anchor. The flukes are at one end of the shank, and the stock is at the other.
she
All boats are referred to as female.
shear pin
A pin attaching one part to another that is designed to break if excessive loads are applied; for example, to connect the propellerto the propeller shaft so that the pin can break if the propeller strikes something, preventing damage to the propeller and engine.
sheathing
A covering to protect the bottom of a boat.
sheave
A wheel used to change the direction of a line, such as in a blockor at the top of the masthead.
sheer
1) The fore and aft curvature of the deck.
2) A sudden change of course.
sheet
A line used to control a sail's trim. The sheets are named after the sail, as in jib sheet and main sheet.
ship
1) A large vessel.
2) To take an object aboard, such as cargo or water.
3) To put items such as oars on the boat when not in use.
shipshape
Neat, orderly and ready to use.
shoal
1) Shallow water.
2) An underwater sand bar or hill that has its top near the surface.
shore
The edge of the land near the water.
shoreline
Where the land meets the water.
shove off
To push a boat, as from a dock or from another boat.
shroud
Part of the standing rigging that helps to support the mast by running from the top of the mast to the side of the boat. Sailboatsusually have one or more shrouds on each side of the mast.
side lights
Green and red lights on the starboard and port sides of the boat, required for navigation at night. Each light is supposed to be visible through an arc of 112.5°, beginning from directly ahead of the boat to a point 22.5° aft of the beam.
sideslip
The tendency of a boat to move sideways in the water instead of along its heading due to the motion of currents or winds.
signal halyard
A halyard used to hoist signal flags.
single sideband
A type of radio carried on a boat to transmit long distances.
sink
1) To go to the bottom of the water.
2) To cause an object to go to the bottom of the water.
skeg
Any flat protrusion on the outside of the hull that is used to support another object, such as the propeller shaft or rudder.
skin
The outside surface of a boat. Usually used when describing afiberglass or other molded hull.
skiff
A small boat.
slack
1) A line that is loose.
2) To ease a line.
slide
Also called a lug. Metal or plastic pieces attached to the forwardedge of a sail to allow easy hoisting of a sail.
sling
1) Lines used to hoist heavy or awkward objects.
2) The act of using such lines to hoist heavy or awkward objects.
3) Ropes used to secure the center of a yard to the mast.
slip
A space between two docks or piers where a boat can bemoored.
sloop
A style of sailboat characterized by a single mast with one mainsailand one foresail.
slot
The opening between the jib and the mainsail. Wind passing through this opening increases the pressure difference across the sides of the mainsail, helping to move the boat forward.
Small World
New World's dinghy.
snap hook
A metal fitting with a arm that uses a spring to close automatically when connected to another object.
snatch block
A block that can be opened on one side, allowing it to be placed on a line that is already in use.
snub
To suddenly stop or secure a line.
snubber
A stretchable line attached between two long pieces of rode to absorb anchor line strain and soften the impact of waves or tidal pull.
sound
1) To measure the depth of the water.
2) A long wide body of water that connects other large bodies of water.
3) A long, wide ocean inlet.
sounding
The depth of the water as marked on a chart.
spar
A pole used as part of the sailboat rigging, such as masts andbooms.
spinnaker
A very large, lightweight sail used when running or on the point of sail known as a broad reach.
spinnaker halyard
A halyard used to raise the spinnaker.
spinnaker pole
Sometimes spinnaker boom. A pole used to extend the foot of the spinnaker beyond the edge of the boat and to secure the corner of the sail.
spinnaker pole lift
Also spinnaker lift. A line running from the top of the mast, used to hold the spinnaker pole in place.
spitfire
A storm jib. A small jib made out of heavy cloth for use in heavy weather. Sometimes brightly colored.
spreaders
Small spars extending toward the sides from one or more places along the mast. The shrouds cross the end of the spreaders, enabling the shrouds to better support the mast.
spring lines
Docking lines that help keep a boat from moving fore and aft while docked.
squall
A sudden intense wind storm of short duration, often accompanied by rain. Squalls often accompany an advancing cold front.
square rigged
A sailboat having square sails hung across the mast.
square sail
A square sail hung from a yard on the mast. Best used when sailing downwind.
SSB
Single sideband radio. A type of radio used on a boat to transmit for long distances.
stability
Ability of a boat to keep from heeling or rolling excessively, and the ability to quickly return upright after heeling.
stability sail
Also riding sail or steadying sail. Any small sail set to help the boat maintain its direction without necessarily moving, as when atanchor or in heavy weather.
staff
A vertical pole on which flags can be raised.
stall
1) To stop moving.
2) Air is said to stall when it becomes detached from the surface it is flowing along. Usually air travels smoothly along both sides of asail, but if the sail is not properly trimmed, the air can leave one of the sides of the sail and begin to stall. Stalled sails are not operating efficiently.
stanchion
A post near the edge of the deck, used to support lifelines.
starboard
The right side of a boat, from the perspective of a person at thestern of the boat and looking toward the bow. The opposite ofport.
starboard tack
A sailboat sailing on a tack with the wind coming over thestarboard side and the boom on the port side of the boat. If two boats under sail are approaching, the one on port tack must give way to the boat on starboard tack.
statute mile
A mile as measured on land, 5,280 feet or 1.6 kilometers. Distances at sea are measured in nautical miles.
stay
Lines running fore and aft from the top of the mast to keep the mast upright. Also used to carry some sails. The backstay is aft of the mast, and the forestay is forward of the mast.
staysail
A triangular sail similar to the jib, set on a stay forward of the mastand aft of the headstay.
stem
The forward edge of the bow. On a wooden boat, the stem is a single timber.
step
1) A fitting for the bottom of the mast.
2) The act of placing the foot of the mast in its step and raising the mast.
stepped
1) A mast that is in place.
2) Where the mast is stepped, as in keel stepped or deck stepped.
stern
The aft part of a boat.
stern light
A white running light placed at the stern of the boat. The stern light should be visible through an arc of 135°, to the rear of the boat.
stern line
A line running from the stern of the boat to a dock when moored.
stiff
A boat that resists heeling.
stink pot
Sailors' slang for a powerboat.
stock
A crossbeam at the upper part of an anchor.
stopper
A mechanical device or knot used to keep a rope from running.
stores
Supplies on a boat.
storm jib
Sometimes called a spitfire. A small jib made out of heavy cloth for use in heavy weather. Sometimes brightly colored.
storm sail
The storm jib and storm trysail. Small sails built from heavy cloth for use during heavy weather.
storm trysail
A very strong sail used in stormy weather. It is loose footed, being attached to the mast but not the boom. This helps prevent boarding waves from damaging the sail or the rigging.
stow
To put something away.
surf
The breaking waves and resulting foam near a shore.
swab
1) A mop made from rope.
2) To use such a mop.
swallow
The place between the sheave and housing of a block, through which a line is run.
swamp
To fill with water.
swell
Large smooth waves that do not break. Swells are formed by wind action over a long distance.
| 
