Safe for Men - A term signifying that the vapor content of a space so certified is less than 0.1 on a gas indicator.

Safe for Men and Fire - A term signifying that the vapor content of a space so certified is 0.1 or less on a gas indicator and that the space contains no oil or sediment which could produce vapors.

Sag (Sagging) - The condition of a vessel caused by the unequal distribution of cargo. When a vessel loads too heavily in the center it causes a bending downward of the hull at the midships area. This can also be caused by the vessel working in heavy seas with large waves under each end and no support under the center of the ship. Sag is the opposite of Hog.

Sampling - The process of obtaining a sample of the material in the tank, container or pipeline to use for testing or other purposes. This can be achieved by automatic or manual means. The following are the most common types of samples taken:

All-Levels Sample - A sample obtained by lowering a weighted, stoppered bottle or beaker or bottle to a point 1 foot (0.3 meter) above the free water level and then, with a sharp jerk of the line opening the sampler and raising it at a rate that it is about 75% full (a maximum of 85% full) as it emerges from the liquid.

Automatic Sample - A sample taken by automatic means. The two basic types of automatic samples are:

Flow-Proportional Sample - A sample taken by an automatic sampler from a pipeline at a rate that is proportional to the liquid flow rate.

Time-Proportional Sample - A sample taken from a pipeline at regular intervals during a batch transfer period.

Bottom Sample - A spot sample taken from the material at the bottom of the tank.

Lower Sample - A spot sample obtained at the midpoint of the lower third of the tank contents.

Middle Sample - A spot sample obtained at the midpoint of the middle of the tank contents.

Running Sample - A sample obtained by submerging an unstoppered beaker or bottle from the surface of the liquid to a point as near as possible to the shore tank draw off point or about one foot above the level of the free water in a ship tank, and then raising it without letting it rest, at a rate so that it will be about 75% full as it emerges from the liquid.

Spot Sample - A sample taken at a specific "spot" within a tank using a stoppered bottle or beaker and lowering it to the level of desired sample then opening it and allowing it to remain at that level until full.

Tap Sample - A sample taken from a valve or connection on a tank or pipeline.

Upper Sample - A spot sample obtained at the midpoint of the upper of the tank contents.

Upper, Middle, Lower Samples - Spot samples taken from the upper third, the middle and lower thirds of the liquid in the tank. The samples so taken may then be composited or analyzed separately.

Salvage - The property which has been recovered from a wrecked vessel, or the recovery of the vessel herself.

Scupper - Any opening or tube leading through the ship's side to carry water away from the deck.

Sea Trials - A series of trials conducted by the builders during which the owner's representatives on board act in a consulting and checking capacity to determine if the vessel has met the specifications.

Seaworthiness - The sufficiency of a vessel in materials constructions, equipment, crew and outfit for the trade in which it is employed. Any sort of disrepair to the vessel by which the cargo may suffer; overloading; untrained officers; may constitute a vessel unseaworthy.

Seaworthiness Certificate - A certificate issued by a classification society surveyor to allow a vessel to proceed after she has me with a mishap that may have affected its seaworthiness. It is frequently issued to enable a vessel to proceed, after temporary repairs have been effected, to another port where permanent repairs are then carried out.

Separation Zone or Line - A zone or line separating traffic proceeding in one direction from traffic proceeding in another direction. A separation zone may also be used to separate a traffic lane from the adjacent inshore traffic zone.

Ship's Agent - A person or firm who transacts all business in a port on behalf of shipowners or charterers. Also called shipping agent; agent.

Shipbreaker - A company that demolishes or cuts up vessels which are obsolete or unfit for sea. The steel is used for scrap.

Ship Chandler - Particular merchants handling ships' stores, supplies, and sundries, etc. Sometimes handles spare parts as accommodation to ship operators.

Shipper - The person for whom the master of a ship agrees to carry cargo. Also called consignor.

Short Ton - A unit of measurement equal to 2,000 pounds.

Sister Ships - Ships built on the same design.

Skin - The plating of a ship.

Slops - A mixture of petroleum and water normally arising from tank washings.

Sludge - A mixture of petroleum and water, usually semi-solid, frequently containing sand and scale.

SOLAS - Safety of Life at Sea Convention.

Sounding - See GAUGING

Special Survey - The survey requirement of a classification society that usually takes place every four years. At the special survey vital pieces of equipment are opened up and inspected by the classification surveyor.

Spill - Oil getting into the sea in any amount for any reason.

Spot Charter - See Voyage Charter.

Spot Market - The market for the immediate charter of a vessel.

Starboard - The right side of a vessel when an observer is facing forward looking toward the bow.

Stern - The after most part of a vessel. The stern will house the steering gear room and various stowage areas. It is that section of a vessel over the rudder and propeller.

Stem - The upright post or bar of the bow.

Stores - A general term for provisions, materials, and supplies used aboard ship for the maintenance of the crew, and for the navigation, propulsion and upkeep of the vessel and its equipment.

Submarine Loading Terminal - A terminal where loading is carried out by means of an offshore hose run along the sea bottom.

Suezmax Carrier - The maximum size ship that can sail through the Suez canal generally considered to be between 120,000-199,999 DWT depending on ships dimensions and draft. See also Vessel Sizes.

Superstructure - Any structure built above the uppermost complete deck such as a pilothouse, bridge, accommodation house etc.