Glossary of Terms

Note: Information in glossary is provided from many sources for the use of the reader.  We have attempted to include what we consider to be the most used terms.  If you need a definition of some other term, please ask.  We probably have your answer in our files.

Accreting Beach Natural build-up of beach due to coastal processes and deposition of suspended sand and other solids. Artificial build up of land by an act of man such as formed by a groin, breakwater or beach fill deposited by mechanical means (trucks, dredges, etc.).
Advance (of a beach) An ongoing seaward movement of the shoreline.
Aft At or near the stern.
Aggradation See Accretion
Alluvial Soil, sand, mud or similar materials deposited by streams.
Along shore Parallel to and near the shoreline.
Along shore waves That portion of the wave front that moves laterally along a beach front.
Amplitude (wave) Magnitude of displacement of a wave from a mean value.
Aquaculture Plant life within the sea or inland waters
Armor Unit Heavy stones placed to protect beach front area.  Large stones or concrete  blocks for solid shoreline protection.
Artificial Nourishment Process of replenishing a beach with material

(usually sand) obtained from another area.
Artificial Reefs Man made structures to initiate revitalization and growth of reefs and eventually barrier islands.
Atoll A ring shaped reef enclosing a lagoon.
Attenuation Lessening the magnitude of a wave.
Awash Situated so that the top is intermittently washed by waves or tidal action.
Back Rush The seaward return of the water following the up rush of the waves.
Back Shore That zone of the shore or beach lying between the fore shore and the coast line comprising the berm or berms and acted upon by waves only during severe storms.
Back Wash (back rush) – Water or waves thrown back by an obstruction such as a ship, bulkhead, breakwater or a cliff.
Bank The rising ground bordering a lake, river or sea.
Bar A submerged or emerged embankment of sand, gravel or other unconsolidated material built up on the sea floor in shallow water by waves and current.
Barrier Island A bar essentially parallel to the shore, the crest of which is above normal high water level.  Provides natural protection from storms for the adjacent coastline
Barrier Lagoon A bay roughly parallel to the coast and separated from the open ocean by barrier islands.
Barrier Reef A reef typically parallel to a shoreline and some distance offshore
Bay A recess in the shoreline or an inlet of a sea between two (2) capes or headlands, not so large as a gulf but larger than a cove.
Bayou A sluggish waterway or creek connecting other streams of water whose course is usually through low lands or swamps.
Beach A zone of unconsolidated material that extends landward from the low water line to the place where there is marked change in material or to the line of permanent vegetation.
Beach Erosion Carving away of beach material by wind, wave, tidal currents, littorial currents, etc..
Beach Face The section of the beach normally exposed to the action of the wave up rush.
Beach Nourishment Typically man made effort to rebuild beaches.  Might be by dredging from offshore or actually hauling in sand, etc. by truck loads and leveling with equipment.
Beach Width Horizontal dimension of the beach normal to the shoreline.
Beaufort Scale A system for rating winds or wave forces by a numbered scale.
Bench Mark A permanently fixed point of known elevation.
Berm Typically a man made dune.
Bluff A high steep bank or cliff.
Boat Basin A naturally or artificially nearly enclosed harbor area suitable for mooring boats.
Bollard A mooring bitt to secure mooring lines.
Bottom The ground or bed under any body of water, the bottom of the sea.  The composition or character of the bed of an ocean or other body of water ; eg – clay, coral, gravel, mud, ooze, pebbles, rock, shell, shingle, hard or soft)
Bow Forward end of boat or ship
Breaker A wave breaking on a shore, over a reef, etc.
Breakwater A floating or fixed structure to protect a shore area, harbor, anchorage or basin from waves. (On a ship) – Fitted “V” shape shield to protect against water shipped over the bow.
Bridge (on a ship) Pilot house That portion of the superstructure where vessel navigation is performed.
Bulkheads Rigid demarcation structures between land and adjacent waters.  Retains or prevents sliding of the adjacent land.  Used when navigable water depths are needed immediately adjacent to the land.  Commonly constructed of interlocking vertical steel members (sheet pile), vertical timbers or plastic/fiberglass composite.  Protects land from wave action.  On occasion may be rock or concrete and shaped to reflect waves in a desirable manner.
Buoy A float moored to the bottom to mark a channel, an anchorage, shoal rock, etc.
By Passing Sand Hydraulic or mechanical movement of sand from the accreting updraft side to the eroding downdraft side of an inlet of harbor entrance.
Canal An artificial water course (large ditch) cut through a land area for such uses as navigation and irrigation.
Canyon A relatively narrow, deep depression with steep slopes the bottom of which grades continuously downward.  May be underwater or on land
Cape A relatively extensive land area jutting seaward from a continent or large island which makes a change in or interrupts the coastal trend.
Capsize A vessel “turning over” due to excessively high center of gravity and loss of transverse stability.  Heavy storm loading on the beam (side) could contribute to capsizing
Causeway A raised road across wet or marshy ground or across water.
Center of Buoyancy The point at which all the vertical forces of buoyancy are considered to be concentrated.  The center of volume of the immersed object
Center of Flotation The center of gravity of the waterplane.
Center of Gravity That point at which all weight is centered.  The center of the total mass.
Channel A natural or artificial waterway which contains moving water or forms a connecting link between two (2) bodies of water.
Chart Datum The plane or level to which soundings (or elevations) or tide heights are referenced.
Chop Short crested waves that may spring up quickly in a moderate breeze and which break easily at the crest.
Cliff A high, steep face of rock or a precipice.
Coast A strip of land of indefinite width that extends from the shoreline inland to the first major change in the terrain features.
Coastal Current Current flowing parallel to the shoreline in deeper water near the surf zone.
Comber A deep water wave whose crest is pushed forward by a strong wind, much larger than a white cap
Come Along Small handy lever operated hoist for pulling items together during assembly activities.
Continental Shelf The zone bordering a continent and extending from the low waterline to the area where there is a rather steep descent to a greater depth.
Cove A small sheltered recess in a coastline, often inside a larger bay or harbor.
Crest of a wave The highest part of a wave – That part of a wave above still water level.
Current Speed of the water flow.
Current – Littorial Any current in the littorial zone caused primarily by wave action.
Cyclone Similar to a Hurricane
Damage Stability Stability of a vessel after flooding
Decay Distance (fetch) The distance waves travel after leaving the generating area.
Decay of Waves The change waves undergo after they leave a generating area (fetch) and pass through a calm or region of lighter winds.  In the process of decay, the wave height decreases and the wave length (period) increases.
Deck Horizontal surface on a ship comparing to a floor in a building
Delta An alluvial deposit, roughly triangular in shape formed at the river mouth.
Density Weight per unit volume of a substance.
Depth The vertical distance from the calm water surface to the sea floor.
Dike A wall or mound built around a low lying area to keep out water.
Displacement Weight of water displaced by a floating object.  Equal to the weight of the object..
Dolphin A cluster of piles.
Down Drift The predominant movement of littorial materials.
Draft The vertical  distance from the bottom of the hull (floating object) to the waterline.
Drift Current A broad shallow slow moving ocean or lake current.
Dunes Sand hill just inland from the active beach.  Ridges or mounds of loose soil materials, usually sand.  Live vegetation helps to stabilize and grow dunes.
Duration In wave forecasting, the length of time the wind blows in nearly the same direction over the fetch (generating area)
Ebb Current The tidal current away from shore, usually associated with the decrease in height of the tide.
Ebb Tide The period of tide between high water and the succeeding low water, a falling tide.
Eddy Circular movement of water at side of main current.  Eddies may be created at points where the main stream passes projecting obstructions or where two (2) currents streams flow counter to each other.
Entrance Access or opening to a navigable channel
Erosion Wasting or wearing away of beach related areas due to natural or man related processes.
Equilibrium The state where there is no movement.
Estuary Part of a river affected by tides. Near mouth of a river where fresh water or river mixes with salt water of the sea.
Fairway That part of a water way that is open and unobstructed for navigation.
Fathom Six (6) Feet.
Fetch Length of open sea or waters directly facing the beach area of interest.
Floating The weight of the volume of water displaced is less than the volume of the vessel or other floating object.
Founder Sinking of floating vessel due to a loss of reserve buoyancy.
Fore At or near the bow.
Freeboard The vertical distance from the waterline to the upper deck of a ship.or similar floating object.
Free Surface Condition when a liquid is free to move within a tank or other vessel.  It causes an effective increase in the height of the Center of Gravity
Groin A shore protection.structure perpendicular to the shoreline.  Traps littorial drift or retards erosion of the shoreline.
Harbor A protected water area for safe mooring of ships or boats.
Heel The transverse angle or inclination of a vessel (results in a list to the side)
Hull Structural body of a ship or other vessel.
Innerbottom Tank tops over double bottom tanks forming an inner skin for the vessel.
Jetty On open sea coasts, a structure extending into a body of water.  Designed to prevent shoaling of a channel by littoral materials to direct and confine the stream or tidal flow.  Built at mouths of rivers or tidal inlets to help deepen and stabilize a channel
Keel Principal for and aft component or member of a vessel or other floating structure located on centerline at the bottom and runs from bow to the stern.
Land To carefully position or lay down an item.
Launching To set the vessel or ship afloat.  May use a launchway or something as simple as a boat trailer.  The boat trailer is probably the handiest means to launch sections of a floating breakwater system.
Levee A dike or embankment to protect land from inundation.
Littorial Transport Movement of sediments in the littorial zone by waves and currents.  Includes both parallel (long shore) and perpendicular (on-off shore) movement.
Littorial Zone The zone extending from the shoreline to just beyond the wave breaking area.
Load The quantity of sediment transported by a current.  Includes the suspended load of small particles and the bed load of large particles that move along the bottom.
Mean Draft That draft of a floating vessel midway between the draft forward and draft aft.
Mooring Securing a ship or other floating system by several lines or cables so as to limit the movement (even with tidal variation).
Nourishment The process of replenishing a beach.  It may be naturally by long shore transport or artificially by deposition of dredged materials
Outfall A structure extending into a body of water for the purpose of discharging sewage, storm run-off or cooling water.
Pass A navigable channel through a bar, reef, shoal or closely adjacent islands.
Permeable As applied to breakwaters – Not solid – The percentage of the volume which may be occupied by water if flooded.  Allows water in and typically reduces wave forces due to internal water actions.  Typical of rock and rubble fixed breakwaters and modular floating breakwaters.
Pier A structure extending out into the water from the shore.  Serves as a landing place, recreational facility, etc. rather than to affect coastal protection.
Pile Heavy timber or steel – concrete section driven into the bottom to serve as a support or protection.
Planning The listing and sequencing of all jobs that must be performed to complete a project.
Quay A section of paved bank or a solid artificial landing place parallel to the navigable waterway for loading or offloading vessels.
Reef An offshore consolidated rock hazard to navigation.
Reflected Wave That part of the incident wave that is returned seaward when a wave impacts on a steep beach, barrier or other reflecting surface.
Reserve Buoyancy The volume of all intact space above the water line.
Revetment A facing or strong concrete, etc. to protect an embankment or shore structure against erosion by wave action or currents,
Rigging Wire rope, fiber rope, tackle, etc. used to secure loose items relative to a vessel or other floating objective.
Rip Rap A protective layer or facing of quarry stone, usually well graded and randomly placed to prevent erosion, scour or sloughing off of an embankment or bluff.
Rolling Period The time it takes a vessel to make a complete roll from port to starboard and back to port.
Rudder A device used to steer a vessel.  Somewhat resembles a flat vertical plate with hinges on the forward edge.
Scour Removal of underwater material by waves and currents, especially at the base or toe of a fixed structure.
Sea Mount An elevation rising more that 1000 meters above the ocean floor and of limited area across the top.
Seawall A structure separating land and water areas, primarily designed to prevent erosion and other damage due to wave action
Secreting Beach Wasting away of beach due to waves and other coastal processes.
Sediment Transport Gradual wearing away of sediments from one beach area and typically depositing on another beach area.
Sheet Pile A pile with a generally slender flat cross section to be interlocked to the adjacent piles to form a diaphragm wall or bulkhead.
Shoal A detached elevation of the sea bottom which may endanger surface navigation
Shoreline The interface between land and the water
Significant Wave A statistical term relating to the one third highest waves of a given group and defined by the average of their heights and periods.
Slack Tank Tank which is not completely filled or empty.
Sounding A measured depth of the water.
Specific Gravity Ratio of the actual weight per unit volume to that of fresh water.
Spit A small point of land or a narrow shoal projecting into a body of water from the shore.
Sponsons Additions to the sides of a hull to increase breadth and stability when vessel inclines.
Stability Tendency of a vessel to return to an erect position after being inclined by a exterior force.
Stem The bow area framing of a floating vessel.
Stern The after area framing of a floating vessel.
Swash Bulkhead Longitudinal bulkhead with or without lightening holes.  Installed for the purpose of reducing free surface effect.
Swell Wind generated waves that have traveled out of their generating area.  Swell exhibits a more regular and longer period and flatter crests than waves within their fetch areas.
Synchronous Rolling When the rolling period of a vessel is the same as the wave period.  A condition to be avoided.
Tidal Current Alternating horizontal movement of water associated with the rise and fall of the tide .
Tidal Period Time interval between the consecutive like phases of the tide.
Tiller An arm attached to the rudder shaft to allow turning of the rudder.
TPI (Tons Per Inch Immersion) Number of tons necessary to change the mean draft of a vessel by one inch.  Will vary with draft and shape of the hull.
Trim Difference between the drafts forward ad aft.
Trough of Wave The lowest point of a waveform between successive crests
Tsunami A long period wave caused by an underwater disturbance such as a colcanic eruption or earthquake.
Volume of Displacement Volume of the water displaced by a floating object.  Weight of the volume of water is equal to the weight of the object.
Waterplane The plane defined by the intersection of the water in which a vessel is floating.
Waterway (man made) May resemble a large ditch, harbor or canal entry in which a vessel might pass through
Wave Period The time for a wave crest to travel a distance equal to one wave length.  Time between successive wave crests.
Wind Waves Waves being formed and built up by the wind.  Any waves generated by the wind.
Windward The direction from which the wind is blowing,