Maritime Injuries Legal Dictionary



Refers to laws and courts with jurisdiction over lawsuits, actions, and disputes which arise from acts done upon or relating to the sea. This includes personal injury maritime lawsuits, and most personal injury offshore lawsuits. It also includes shipping disputes and vessel collisions and allisions.

Admiralty law originated in ancient times. One of the first bodies of maritime law was Rhodian Sea Law (Nomos Rhodion Nautikos). Traditionally admiralty courts were separate from normal civil or “common law” courts. One of the important historical distinctions between admiralty and common law courts was that admiralty courts did not provide for jury trials.

Pre-revolution admiralty courts in the United States and England did not rely on English common law, but rather were based on the Roman Corpus Juris Civils civil codes.

The term “admiralty” comes from “admiral,” the name for the highest ranking maritime military official. The term “admiral” is derived from a combination of the Arabic term for “commander of the sea” and the Latin term for “admirable.”


The aft of a ship or vessel is the area toward the rear. It is the opposite of the fore of a ship or vessel.
“Aft” comes from the Old English word æftan, which means “from behind.”


The definition of an allision is when a ship or other vessel strikes a fixed object, which may include another ship or vessel that is anchored or simply not moving.
An allision is distinguishable from a collision, which is when two moving vessels strike each other.
The word allision comes from the Latin term allisio, which means “to strike or dash against.”
Many maritime personal injuries arise from vessel allisions and collisions.

Archimedes’ Principle

Used to determine a vessel’s buoyancy, in other words how well it can float.
Basically, if the weight of the water displaced by a vessel is less than the weight of the vessel itself, the object will sink. If it is less, the vessel will float.
If a vessel is not sufficiently buoyant, it may be more susceptible to capsizing, which can result in severe personal injuries and wrongful deaths.

Attending Vessel

A vessel which is moored close to and readily accessible from an OCS facility for the purpose of providing power, fuel, or other services to the operation being conducted on the facility.


Lower point of the inner hull of a ship, offshore drilling rig, tanker, or other vessel.
Billy Pugh Basket
A personnel basket used along with a crane to transfer offshore and maritime workers from platforms and vessels. Many offshore and maritime accidents involve the use of Billy Pugh baskets.


Abbreviation of Bureau of Ocean Energy Management.

BOEMRE inspector

An individual employed by the Bureau of Ocean Energy Management, Regulation and Enforcement who inspects fixed OCS facilities on behalf of the Coast Guard to determine whether the requirements of this subchapter are met.


The front of an offshore drilling unit, ship, tanker, or other vessel.


Abbreviation for Bureau of Safety and Environmental Enforcement.


An anchored float typically used as a navigation mark. Buoys may be used to mark a particular location, reef, or hazard.


How well an object floats.
Buoyancy comes from the Spanish word boyar, which means “to float.”
Bureau of Ocean Energy Management
Legal governmental body that ensures offshore oil and gas and other minerals are “made available for expeditious and orderly development, subject to environmental safeguards, in a manner which is consistent with the maintenance of competition and other national needs.” This includes resource evaluation, planning, and leasing.
BOEM was created following the Deepwater Horizon explosion, an offshore accident which caused many personal injuries and deaths.
Bureau of Ocean Energy Management, Regulation and Enforcement
Formerly the Minerals Management Service (MMS), the federal government body that promotes and regulates oil and gas and mineral development offshore. The organization was split into the Bureau of Ocean Energy Management (BOEM) and the Bureau of Safety and Environmental Enforcement (BSEE) as part of a major reorganization following the Deepwater Horizon explosion, an offshore disaster which killed 11 offshore workers and injured many more.

Bureau of Safety and Environmental Enforcement

The agency, abbreviated BSEE, exercises the safety and environmental enforcement functions, including the authority to inspect, investigate, summon witnesses and produce evidence, levy penalties, cancel or suspend activities, and oversee safety, response, and removal preparedness.
One of the organization’s jobs is to prevent offshore and maritime injuries.


In maritime law, a ship or vessel collision is when two moving ships or vessels strike each other.
In its strictest sense, a collision is different than an allision, which involves only one moving vessel and another stationary vessel or object. “Common usage, however, applies the term equally to cases where a vessel is run foul of when entirely stationary, or is brought in contact with another by swinging at her anchor.” The Moxey, 1 Abb. Adm. 73 (S.D.N.Y. 1847).
Vessel collisions involve a tremendous amount of force and often result in severe personal injuries to

Commandant of the Coast Guard

The United States Coast Guard’s service chief and highest-ranking member.
Contract of Affeightment
Under maritime law, when a ship owner and its vessel(s) and crew(s) are hired to carry a number of cargoes within a specified period of time on a specified route. More than one ship may be involved.


The legal requirement that a shipowner provide free medical care to injured seaman.
A maritime injury lawyer may be able to assist an injured offshore worker or seaman whose employer refuses to provide adequate medical treatment.
Demise Charter (Bareboat Charter)
Under maritime law, when a vessel is contracted but the vessel owner does not crew the boat. The charterer receives possession and full control, as well as with the legal and financial responsibility for the vessel. This is common for tankers and bulk-carriers and may have Jones Act implications when a member of the crew is injured.


The vertical distance between the waterline and the bottom of a ship or vessel’s hull. It is the minimum safe operating depth of a crewboat, offshore drilling rig, ship, supply vessel, tanker, tugboat, or other vessel.


Dredging means to clean out the bed of a body of water such as a harbor, river, or ship channel.  This is done by special vessels often referred to as “dredges.”

Drilling Contractor

In offshore drilling injury cases, the drilling contractor is the company hired by the oil company (operator) to drill offshore oil and gas wells. The drilling contractor is also referred to as the “driller” or the “contractor” in offshore drilling contracts.


A drillship is a vessel used primarily to explore new oil and gas wells.  Most drillships are capable of drilling in ultra-deepwater and are kept in place through advanced computer-controlled dynamic positioning systems.  Historically drillships have been faster and more maneuverable than other mobile offshore drilling units such as semisubmersibles, but have tradeoffs including less variable deckload and more susceptibility to ocean motions.

Personal injury and wrongful death lawsuits have been filed arising out of accidents on drillships, just as with other MODUs.  Our Houston injury lawyers are ready to help Jones Act seamen and other workers injured on drillships.

Dynamic Positioning

Dynamic Positioning or “DP” is means of keeping a mobile offshore drilling unit (MODU) or other vessel in place through the use of computer-controlled thrusters and propellers.  DP systems enable vessels to operate in much deeper water.

Serious personal injuries can occur, however, when there is a DP failure.  For example, a DP failure on a connected well can result in a driftoff, explosion, or oil spill.

Fixed OCS Facility

A bottom founded OCS facility permanently attached to the seabed or subsoil of the OCS, including platforms, guyed towers, articulated gravity platforms, and other structures.

Floating OCS Facility

A buoyant OCS facility securely and substantially moored so that it cannot be moved without a special effort. This term includes tension leg platforms and permanently moored semisubmersibles or shipshape hulls but does not include mobile offshore drilling units and other vessels.


The front of an offshore drilling rig, ship, or other vessel. The opposite of “aft.”


Something attached to the inside of a ship or vessel.

Jack Up Rig

A mobile offshore drilling rig that has movable legs that raise it above the sea.  Typically jack-up rigs can drill in 350 feet of water.

Offshore injuries numbing in the thousands have occurred on jack-up rigs since the first jackup, the Gus I, went into operation in 1954.

Jones Act

The Jones Act is federal legislation that protects American offshore and maritime workers who are injured at sea. Unlike traditional workers’ compensation, this law provides minimal automatic compensation (maintenance and cure), but allows qualifying seamen involved in accidents or who become sick while performing their duties to sue their employers, usually with the assistance of a maritime injury lawyer or offshore injury lawyer.


The keel of a vessel is the bottom backbone of its hull. It runs running longitudinally along the center of the hull bottom.


The side of a vessel away from the wind.

Locality Test

The traditional maritime law test for personal injury jurisdiction was the “locality” test.
The United States Supreme Court created the locality test in the case of the The Plymouth, 70 U.S. 20 (1865), which stated that “[e]very species of tort, however occurring, and whether on board a vessel or not, if upon the high seas or navigable waterways is of admiralty cognizance.”
The locality test has been modified over the years, because of situations courts found led to absurd results under a pure locality test. For example, the locality test would mean that admiralty principles apply to a swimming accident.


The legal requirement that a shipowner provide an injured seaman with basic living expenses while he is injured. An offshore injury lawyer may assist an injured seaman in filing a lawsuit if the employer pays inadequate maintenance, or fails to pay maintenance at all.

Manned OCS Facility

An OCS facility on which people are routinely accommodated for more than 12 hours in successive 24 hour periods.

Manned OCS Platform

A fixed OCS facility on which people are routinely accommodated for more than 12 hours in successive 24 hour periods.

Marine Inspector

A person designated as such by a United States Coast Guard Officer in Charge, Marine Inspection, to perform inspections of units to determine whether or not the requirements of laws administered by the Coast Guard and of Coast Guard regulations are met.

Maritime Investigating Officer

A person assigned by the United States Coast Guard Commandant, a District Commander, or an Officer in Charge, Marine Inspection, to conduct an investigation of an accident, casualty, or other incident.

Maritime Jurisdiction Test

After rejecting the locality test, United States courts have fashioned a multifactor test for admiralty jurisdiction in personal injury cases.
This typically involves evidence that the personal injury incident (1) occurred on a navigable waterway (the traditional locality test); (2) has a substantial relationship to traditional maritime activity; and (3) could potentially disrupt maritime commerce.
The “potential to disrupt maritime commerce” element of maritime law jurisdiction does not require that a personal injury accident occur during a commercial maritime activity. For example, maritime law may apply when a person suffers a personal injury during a crash between two pleasure crafts.

Maritime Law

The body of laws that govern matters involving ships and shipping.
Maritime law applies and provides injured offshore maritime workers, seaman, crewmen, and sailors with special legal rights including the ability to pursue lawsuits for damages.
Depending on the circumstances, maritime law may also apply to people who are not maritime workers but who are injured on a vessel.
Consult with an offshore injury attorney, maritime injury attorney, or Jones Act attorney if you or a loved one has been injured, or a loved one has died, on an offshore drilling rig, ship, tanker, tugboat, or other vessel. Morrow & Sheppard are available to assist, provide free consultations, and we only get paid when our clients win.
Maritime Law Association of the United States
Founded in 1899 and arguably the largest and most prestigious organization of maritime and offshore lawyers, the MLA advances reforms in the Maritime Law of the United States, facilitates justice in its administration, promotes uniformity in the enactment and interpretation of Maritime Law, and furnishes a forum to discuss problems affecting Maritime Law and its administration, and acts with other associations in efforts to bring about a greater harmony in the shipping laws, regulations and practices of different nations.
Attorneys at Morrow & Sheppard LLP have membership in the Maritime Law Association.

Minerals-Offshore Oil and Gas

Oil, gas, sulphur, geopressured-geothermal and associated resources, and all other minerals which are authorized by an Act of Congress to be produced from “public lands.”


Abbreviation of the Maritime Law Association of the United States.

Mobile Offshore Drilling Unit

Vessel, other than a public vessel of the United States, capable of engaging in drilling operations for exploration or exploitation of subsea resources.
Mobile offshore drilling units include drillships, drilling vessels, semisubmersibles, submersibles, jack-ups, and similar facilities that can be moved without substantial effort. Many are self-propelled.
Workers who are injured aboard mobile offshore drilling units may be entitled to personal injury compensation under the Jones Act or maritime law.


Abbreviation for Mobile Offshore Drilling Unit.


One of the requirements for admiralty law jurisdiction is navigability.
What is a navigable waterway? Generally speaking, a body of water is navigable if it is deep and wide enough for vessels and ships to pass through.
In some nations, including England, a waterway is only “navigable” for maritime law purposes if it is subject to the tides. That is not the case in the United States, where lakes, streams, rivers, and other bodies of water can constitute navigable waterways.
The United States Supreme Court set out the test for navigable waterways in the case of The Daniel Ball, 77 U.S. 570 (1870):
“Those rivers must be regarded as public navigable rivers in law which are navigable in fact. And they are navigable in fact when they are used or are susceptible of being used in their ordinary condition as highways for commerce over which trade and travel are or may be conducted in the customary modes of trade and travel on water. And they constitute navigable waters of the United States within the meaning of the acts of Congress, in contradistinction from the navigable waters of the states, when they form in their ordinary condition by themselves, or by uniting with other waters, a continued highway over which commerce is or may be carried on with other states or foreign countries in the customary modes in which such commerce is conducted by water.”

Oceans Motions

A program used on Mobile Offshore Drilling Units to measure the draft and stability of the vessel and to perform load testing.


The abbreviation for Outer Continental Shelf.

OCS Activity

OCS activity means any offshore activity associated with exploration for, or development or production of, the minerals of the Outer Continental Shelf.

OCS Facility

Any artificial island, installation, or other device permanently or temporarily attached to the subsoil or seabed of the Outer Continental Shelf, erected for the purpose of exploring for, developing, or producing resources therefrom, or any such installation or other device (other than a ship or vessel) for the purpose of transporting such resources. The term includes mobile offshore drilling units when in contact with the seabed of the OCS for exploration or exploitation of subsea resources.
Every year, many offshore workers suffer serious personal injuries while working on an OCS Facility. The Houston offshore injury lawyers at Morrow & Sheppard are privileged to assist injured offshore workers and their families nationwide.


The abbreviation for the Outer Continental Shelf Lands Act.

Officer in Charge, Marine Inspection

A person who commands a Marine Inspection Zone described and who is immediately responsible for the performance of duties with respect to inspections, enforcement, and administration of regulations governing units.

Offshore Injury Lawyers

Offshore injury lawyers include personal injury lawyers who handle cases arising from accidents offshore. This includes accidents off the coast of the Gulf of Mexico. Offshore injury cases often stem from accidents on floating drilling rigs (usually covered by the Jones Act), accidents on fixed platforms (often covered by OCSLA), basket transfer accidents and billy pugh accidents, swing rope accidents, helicopter crashes, and accidents on crewboats and supply vessels (typically covered by the Jones Act or general maritime law).

Offshore Oil and Gas Development

Activities which take place following discovery of minerals in paying quantities, including, but not limited to, geophysical activity, drilling, and platform construction, and which are for the purpose of ultimately producing the minerals discovered.
Thousands of injuries and deaths have occurred during offshore oil and gas development.

Oil and Gas Exploration

The process of searching for oil, gas, and other minerals, including, but not limited to, (1) geophysical surveys where magnetic, gravity, seismic, or other systems are used to detect or imply the presence of such minerals, and (2) any drilling, whether on or off known geological structures, including the drilling of a well in which a discovery of oil or natural gas in paying quantities is made and the drilling of any additional delineation well after the discovery which is needed to delineate any reservoir and to enable the lessee to determine whether to proceed with development and production.

Operator (Offshore Oil and Gas)

The operator is the entity that owns the right to drill for offshore oil and gas. In other words, an oil company.

Operator (Vessel)

A charterer by demise or any other person who is responsible for the operation, manning, victualing, and supplying of the vessel.


Something attached to the outside of a ship or vessel.

Outer Continental Shelf

The Outer Continental Shelf or “OCS” is the seabed and subsoil of the submarine areas that the United States has sovereign rights over, but that are not within the jurisdiction of a state such as Texas, Louisiana, Mississippi, Alabama, or Florida. The federal government leases portions of the OCS for the development of oil and gas and other minerals.
Personal injury accidents that occur on the Outer Continental Shelf may be covered by the Outer Continental Shelf Lands Act or “OCSLA,” maritime law, or the Jones Act.
The Outer Continental Shelf is divided into four regions:

  • Gulf of Mexico OCS Region
  • Atlantic OCS Region
  • Pacific OCS Region
  • Alaska OCS Region

If you or a loved one has been injured while working offshore or on a maritime vessel on the Outer Continental Shelf, please contact Morrow & Sheppard. Our offshore injury and maritime lawyers assist victims and families nationwide.

Outer Continental Shelf Lands Act

Created in 1953, the Outer Continental Shelf Lands Act, 43 U.S.C § 1331 et seq., provides the Secretary of the Interior with authority to lease, for oil and gas and mineral development, submerged land in the continental shelf that is outside state territorial waters but within federal jurisdiction.
In personal injury cases, if OCSLA applies, the law of the adjacent state often applies as the “borrowed law.”
Louisiana territorial waters extend 3.5 miles (3 nautical miles) “seaward of the baseline from which the breadth of the territorial sea is measured.” This “baseline” is the low water mark, essentially shore. Texas territorial waters extend 10.36 miles (9 nautical miles) from the “baseline” or shore. All other states are 3.452 miles (3 nautical miles) from the “baseline” or shore.
Federal waters extend to the farthest of (1) 230 miles (100 nautical miles) seaward of the territorial waters baseline; (2) if the shelf exceeds 230 miles, not longer than 115 miles from the 2,500 meter isobath or a line 403 miles (350 nautical miles) from the baseline.

Port (vessel side)

The port side of a ship or vessel is the left side when standing on the deck and facing forward.

Production (oil and gas)

Activities which take place after the successful completion of any means for the removal of minerals, including, but not limited to, such removal, field operations, transfer of minerals to shore, operation monitoring, maintenance, and workover.

Saving To Suitors Clause

Personal injury maritime lawsuits and offshore injury lawsuits may be brought in state court under the “Saving to Suitors” Clause.
28 U.S. Code § 1333, entitled “Admiralty, maritime, and prize cases” provides that federal “district courts shall have original jurisdiction, exclusive of the courts of the States, of: . . . [a]ny civil case of admiralty or maritime jurisdiction, saving to suitors in all cases all other remedies to which they are otherwise entitled.” This is the “Saving to Suitors” Clause.
The background is that the United States Constitution, Article III, §2, provides that the U.S. Supreme Court, as well as any lower courts created by Congress, shall have jurisdiction over “all cases of admiralty and maritime jurisdiction.” When it created the lower federal courts, Congress expressly limited admiralty jurisdiction, reserving state court jurisdiction over certain matters under the “Saving to Suitors” Clause.
The “Saving to Suitors” Clause provides state courts with concurrent jurisdiction over maritime claims as long as the claims do not require a purely maritime remedy (such as seizure of a vessel) and so long as state jurisdiction is not specifically prohibited by statute (such as the Foreign Sovereign Immunities Act, Ship Mortgage Act, Limitation of Liability Act, Suits in Admiralty, and Public Vessels Act).


A semi-submersible, “semisubmersible,” or “semi” is a specialized vessel typically used to drill for oil and gas.  It is a platform vessel typically supported by ballasted pontoons.

The pontoons of a semisubmersible drilling rig generally sit below the ocean surface (except, for example, when the rig is in transit or emergency escape mode).

Semisubmersibles are generally considered more stable than their primary deepwater competitor, the drillship.  They also typically have larger decks and can accommodate greater variable deckload.

Most modern semisubmersibles stay in place or “station keep” using sophisticated dynamic positioning systems.

Thousands of personal injuries and numerous wrongful deaths have occurred due to dangerous conditions and unsafe work practices on semisubmersible drilling rigs.


A vessel’s stability refers to how well it behaves in still waters and rough seas. How stable a vessel is during a pitch (side-to-side movement) or a roll (front-to-back movement) directly relates to whether or not the vessel is safe. Offshore drilling rigs, ships, tankers, and other vessels that are not stable can cause or contribute to offshore personal injuries and maritime personal injuries.

Standby Vessel

A vessel specifically designated in an Emergency Evacuation Plan to provide rapid evacuation assistance in the event of an emergency.


The right side of a ship or vessel, when standing on the deck and facing forward.


The stern of a vessel is the most rearward part. Technically, it is the area over the sternpost, although the term is commonly used to refer generally to the rear of a vessel. A ship’s stern is usually lit white at night.

Time Charter

Under maritime law, when a vessel is hired for a specific period of time. The owner manages the vessel and crew but the charterer selects the ports and directs the vessel where to go. The charterer pays a daily hire to the vessel owner as well as fuel costs, port charges, and commissions.


The area on the main exposed deck of a ship or vessel.
On an offshore drilling rig, “topside” often refers to the drilling equipment area on the top deck. Many personal injury offshore accidents occur on the topside drill floor.

United States Coast Guard

United States military branch charged with enforcing maritime law.
The Coast Guard was created in 1790 and is the oldest continuous seagoing service of the United States.

Unmanned Facility (OCS)

An OCS facility, other than a floating facility or mobile offshore drilling unit, which is not a manned facility even though it may be continuously serviced by an attending vessel.

Unmanned Platform (OCS)

A fixed, bottom-founded OCS facility which is not a manned facility even though it may be continuously serviced by an attending vessel.


Abbreviation for United States Coast Guard.


Under maritime injury law, vessels include watercraft and other artificial contrivances used, or capable of being used, as a means of transportation on water. The term “vessel” is not limited to ships engaged in commerce. Jack-up rigs, semisubmersibles, drillships, crewboats, tankers, supply boats, FSPOs are examples of craft that may qualify as “vessels” but are not ships.
In offshore injury cases and maritime injury cases, vessel status is important, as it may determine whether the Jones Act or maritime law applies.

Voyage Charter

Under maritime law, a voyage charter is when a vessel and its crew are hired for a voyage. The charterer pays the vessel owner per ton or on a lump sum basis, and the owner pays port costs, fuel costs, and crew costs, but not stevedoring costs.


Where the surface of the water meets the hull of an offshore drilling rig, ship, tanker, or other vessel.


The side or direction of a ship or vessel from which wind blows; also called the “weather” side. The opposite of the leeward side of a vessel.

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