The stability conditions of

watercraft Any vehicle used in or on water as well as underwater, including boats, ships, hovercraft and submarines, is a watercraft, also known as a water vessel or waterborne vessel. A watercraft usually has a propulsive capability (whether by sai ...

are the various standard loading configurations to which a

ship A ship is a large watercraft that travels the world's oceans and other sufficiently deep waterways, carrying cargo or passengers, or in support of specialized missions, such as defense, research, and fishing. Ships are generally distinguished ...

boat A boat is a watercraft of a large range of types and sizes, but generally smaller than a ship, which is distinguished by its larger size, shape, cargo or passenger capacity, or its ability to carry boats. Small boats are typically found on i ...

, or

offshore platform An oil platform (or oil rig, offshore platform, oil production platform, and similar terms) is a large structure with facilities to extract and process petroleum and natural gas that lie in rock formations beneath the seabed. Many oil platfor ...

may be subjected. They are recognized by classification societies such as

Det Norske Veritas DNV (formerly DNV GL) is an international accredited registrar and classification society headquartered in Høvik, Norway. The company currently has about 12,000 employees and 350 offices operating in more than 100 countries, and provides serv ...

Lloyd's Register Lloyd's Register Group Limited (LR) is a technical and professional services organisation and a maritime classification society, wholly owned by the Lloyd’s Register Foundation, a UK charity dedicated to research and education in science and ...

and

American Bureau of Shipping American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the " United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, p ...

(ABS). Classification societies follow rules and guidelines laid down by

International Convention for the Safety of Life at Sea The International Convention for the Safety of Life at Sea (SOLAS) is an international maritime treaty that sets minimum safety standards in the construction, equipment and operation of merchant ships. The International Maritime Organization ...

(SOLAS) conventions, the

International Maritime Organization The International Maritime Organization (IMO, French: ''Organisation maritime internationale'') is a specialised agency of the United Nations responsible for regulating shipping. The IMO was established following agreement at a UN conference ...

and laws of the country under which the vessel is flagged, such as the

Code of Federal Regulations In the law of the United States, the ''Code of Federal Regulations'' (''CFR'') is the codification of the general and permanent regulations promulgated by the executive departments and agencies of the federal government of the United States. ...

. Stability is normally broken into two distinct types: intact and damaged.

Intact stability

The vessel is in normal operational configuration. The hull is not breached in any compartment. The vessel will be expected to meet various stability criteria such as GMt (metacentric height), area under the GZ (righting lever) curve, range of stability, trim, etc.

Intact conditions

Lightship or Light Displacement

The vessel is complete and ready for service in every respect, including permanent

ballast Ballast is material that is used to provide stability to a vehicle or structure. Ballast, other than cargo, may be placed in a vehicle, often a ship or the gondola of a balloon or airship, to provide stability. A compartment within a boat, ship ...

, spare parts, lubricating oil, and working stores but is without fuel, cargo, drinking or washing water, officers, crew, passengers, their effects, temporary ballast or any other variable load."Definition of Light Displacement at Naval Vessel Register"
/ref>

Full load departure or full displacement

Along with all the Lightship loads, the vessel has all systems charged meaning that all fresh water, cooling, lubricating, hydraulic and fuel service header tanks, piping and equipment systems are filled with their normal operating fluids. Crew and effects are at their normal values. Consumables (provisions, potable water and fuel) are at 100% capacity. Ammunition and/or cargo is at maximum capacity. The vessel is at its limiting

draft Draft, The Draft, or Draught may refer to: Watercraft dimensions * Draft (hull), the distance from waterline to keel of a vessel * Draft (sail), degree of curvature in a sail * Air draft, distance from waterline to the highest point on a vesse ...

or legal

load line Load line may refer to: * Ship's load line The waterline is the line where the hull of a ship meets the surface of the water. Specifically, it is also the name of a special marking, also known as an international load line, Plimsoll line and ...

Standard condition

This is only for military vessels. Along with all the Lightship loads, the vessel has all systems charged meaning that all fresh water, cooling, lubricating, hydraulic and fuel service header tanks, piping and equipment systems are filled with their normal operating fluids. Crew and effects are at their normal values. Consumables (provisions, potable water and fuel) are at 50% capacity. Ammunition and/or cargo is at 100% capacity. This condition is normally used for range and speed calculations.

Light arrival

Along with all the Lightship loads, the vessel has all systems charged meaning that all fresh water, cooling, lubricating, hydraulic and fuel service header tanks, piping and equipment systems are filled with their normal operating fluids. Crew and effects are at their normal values. Consumables (provisions, potable water and fuel) are at 10% full load. Ammunition and/or cargo is at 100% capacity.

Damaged stability

The vessel in the assessed "Worst Intact Condition" is analytically damaged by opening various combinations of watertight compartments to the sea. The number of compartments and their location are dictated by IMO regulations, SOLAS conventions, or other applicable rules. Typically these conditions are identified by the compartment(s) damaged ex: "Hold #3 and Water Ballast Tank 4 Port"

References

{{Reflist

External links

nvr.navy.mil, definitions
Displacement Naval architecture Ship measurements de:Stabilität (Schifffahrt) el:Καμπύλη ευστάθειας nl:Stabiliteit (schip)