Extended Operational and Trade Vocabulary

Hydrographic Offices, Survey Vessels and Marine Cartography glossary

Vocabulary of hydrography and nautical charting: acoustic Doppler current profilers and bottom-track modes, UKHO ADMIRALTY chart series, distance tables and digital products like e-Navigator and EasyTide, survey-vessel instrumentation, and the national hydrographic offices and cartographic standards behind chart production and updating by Notices to Mariners.

344 defined terms.

Showing 250 on this page (page 1 of 2).

A

ADCP (Acoustic Doppler Current Profiler): Sonar instrument that measures water current velocity across a depth profile using the Doppler shift of acoustic returns from suspended particles. Teledyne RDI Workhorse and Ocean Surveyor models…
ADCP Bottom Track: Mode in which an ADCP measures vessel speed over ground by pinging the seabed, supporting precise survey navigation and current vector resolution.
ADMIRALTY Charts: UKHO paper and digital chart series covering global waters, distributed through certified ADMIRALTY chart agents and updated weekly by Notices to Mariners.
ADMIRALTY Distance Tables (NP 350): UKHO publication tabulating great-circle and rhumb-line distances between commercial ports, used for voyage planning and freight calculations.
Admiralty e-Navigator: The UKHO desktop planning and chart management application for managing ENC and publication holdings.
Admiralty EasyTide: The free UKHO online tidal prediction service for ports worldwide.
ADMIRALTY List of Lights and Fog Signals (NP 74 to NP 84): Eleven-volume UKHO series listing characteristics, ranges, and structures of lit aids to navigation worldwide.
Admiralty List of Radio Signals (ALRS): UKHO series NP281 to NP286 covering radio communications, satellite services, radio aids, meteorology, GMDSS and pilot services.
ADMIRALTY Nautical Publications (ANPs): Digital editions of UKHO Sailing Directions, Lists of Lights, Lists of Radio Signals, Tide Tables, and Mariner's Handbook delivered via AVCS workflows.
ADMIRALTY Sailing Directions (Pilots): UKHO Pilot books NP 1 to NP 72 describing coastal features, port approaches, and navigational hazards for the world's oceans.
Admiralty Tide Tables (ATT): UKHO publications NP201 to NP204 giving tidal predictions worldwide.
Admiralty TotalTide: ATT software providing seven-day tidal height and stream predictions for over 7,000 ports.
ADMIRALTY Vector Chart Service (AVCS): UKHO official ENC distribution service holding more than 17,000 charts from 70 producing nations, sold by license through chart agents.
AHO Wollongong: Headquarters of the Australian Hydrographic Office at HMAS Albatross airfield site, Wollongong, New South Wales, which became the official charting authority for Australia.
AML Minos-X: Multi-parameter sonde from AML Oceanographic accepting interchangeable Xchange sensor heads for sound velocity, conductivity, temperature, and turbidity.
AML Oceanographic: Canadian manufacturer based in Sidney, British Columbia, producing modular Xchange sound velocity sensors and CTD instruments used on multibeam survey platforms.
AML Smart Sensors: Plug-and-play oceanographic sensor family in which calibration data resides on the sensor itself, simplifying field swaps on survey launches.
Apex Predator Survey Launch: NOAA hydrographic survey launch class deployed from Thomas Jefferson and other coastal mapping ships for shallow-water multibeam work.
Aquaculture Charting: Hydrographic depiction of fish farms, mussel lines, and oyster leases on ENCs and paper charts, often using IHO object class OBSTRN with category aquaculture.
ARCS (ADMIRALTY Raster Chart Service): UKHO raster chart product set of digital scans of paper ADMIRALTY charts, gradually superseded by AVCS vector coverage.
Areal Bathymetry: Two-dimensional gridded depth product derived from swath sonar coverage, typically delivered as GeoTIFF or BAG files.
Argo Float Program: International network of more than 3,900 autonomous profiling floats measuring temperature and salinity to 2,000 meters, coordinated by national hydrographic and oceanographic agencies.
ASV C-Worker: Autonomous surface vessel range from L3Harris ASV used for hydrographic survey, sometimes deployed alongside crewed survey ships to extend swath coverage.
AusENC: Distribution service of Australian ENCs from the AHO, integrated into AVCS and Primar catalogs.
Australian Hydrographic Office (AHO): Royal Australian Navy organization, established in 1942, responsible for charting Australian waters and producing AusENC and AUS-series paper charts.

B

BAG (Bathymetric Attributed Grid): Open Navigation Surface format storing gridded depth, uncertainty, and metadata in HDF5 containers, mandated by NOAA OCS for survey deliverables.
Baseline Recovery: Hydrographic field operation to relocate and confirm horizontal control monuments before establishing GNSS reference stations for a survey.
Bathymetric Lidar: Airborne laser system using a green wavelength near 532 nanometers to penetrate water and map shallow bathymetry, typified by Teledyne CZMIL and Leica Chiroptera sensors.
Bathymetric Surface (S-102): IHO product specification within the S-100 framework defining gridded depth and uncertainty for navigational decision support.
Bathymetry: Measurement and mapping of seafloor depth.
Beam Steering: Multibeam sonar technique of electronically forming receive beams at calculated angles using delay-and-sum processing on the hydrophone array.
Beam Width: Angular extent of an acoustic beam, expressed in degrees, controlling along-track and across-track resolution of multibeam soundings.
Belgica (RV): Belgian Federal Science Policy Office research vessel commissioned in 2021, built by Freire Shipyard in Vigo, operated by RBINS for North Sea oceanographic and hydrographic work.
Benthic Habitat Mapping: Classification of seabed substrate and biological cover from acoustic backscatter and ground-truth grabs, increasingly produced alongside hydrographic surveys.
BlueROV2: Small open-architecture electric observation ROV from BlueRobotics offered in heavy and standard configurations.
Breaker Line Charting: Depiction of surf-zone breakers on ENCs using object SBDARE with attribute NATSUR, particularly important on exposed coastlines.
BSH Hamburg: Bundesamt fuer Seeschifffahrt und Hydrographie, Germany's federal maritime and hydrographic agency headquartered at Bernhard-Nocht-Strasse 78, Hamburg, with a second office in Rostock.
BSH Wreck Database: Comprehensive German wreck and obstruction register maintained by BSH for the North Sea and Baltic, feeding ENC updates.
BWB (Backscatter Worldwide): Acoustic backscatter mosaic concept used in seabed classification, normalized for incidence angle and absorption losses.

C

C-MAP: A vector chart brand originally of Norway, now part of Navico Group, producing CM93 and ECDIS-grade ENCs.
CAATS II (Computer Assisted Approval and Tracking System): NOAA OCS workflow software used to track survey data from field acquisition through chart compilation.
Calibration Line: Multibeam patch-test track run over a known target to estimate pitch, roll, yaw, and timing biases between the sonar and inertial sensors.
CARIS Bathy DataBASE: Geospatial database from Teledyne CARIS managing multi-resolution bathymetric grids and feature data for chart production.
CARIS HIPS and SIPS: Teledyne CARIS hydrographic and side-scan processing suite widely used by hydrographic offices for sounding cleaning and product generation.
CARIS S-57 Composer: Tool for compiling and validating S-57 ENC cells used by several national hydrographic offices.
Cartographer: Specialist who compiles hydrographic and other source data into charts, applying IHO S-4 specifications and house style rules.
Cartographic Generalization: Selection and simplification of features when compiling a chart at a smaller scale, governed by S-4 sections on density and clarity.
Catalogue of Nautical Charts (NP 131): UKHO publication listing all ADMIRALTY paper charts, their coverage, and edition numbers.
Cavitation Noise: Acoustic interference from propeller cavitation that degrades multibeam data; survey vessels often have specially designed quiet propellers.
Cell (ENC): S-57 file containing chart data for a defined geographic area, named with an eight-character code where the first two letters identify the producer nation.
Cell Permit: An S-63 encrypted authorisation that unlocks one ENC cell for a defined period.
Centre for Coastal and Ocean Mapping (CCOM): University of New Hampshire research center partnering with NOAA on multibeam algorithms and the Open Navigation Surface BAG format.
Chart datum: Lowest astronomical tide reference for hydrographic charts.
Chart Number 1 (INT 1): International symbol guide defining the symbols, abbreviations, and terms used on nautical charts under IHO S-4.
China MSA Cartographic Center: Cartographic division of the China Maritime Safety Administration responsible for Chinese chart series and ENC production.
Chirp Sonar: Sub-bottom or side-scan technique transmitting a frequency-modulated pulse to improve range resolution through pulse compression.
CHS Ottawa: Canadian Hydrographic Service headquarters at 615 Booth Street, Ottawa, with regional offices in Burlington, Quebec City, Mont-Joli, and Sidney, British Columbia.
CMRP (Center of Motion Reference Point): Survey vessel reference point at which all sensor offsets are referenced, typically near the keel below the inertial unit.
Co-tidal Chart: Chart showing lines of equal high-water phase, supporting tidal prediction in shallow seas.
Coast Pilot (NOAA): Nine-volume NOAA publication describing US coastal navigation features, complementing the chart series.
Coastal Survey Vessel (CSV): NOAA hull class including Thomas Jefferson and Ferdinand R Hassler, designed for inshore multibeam mapping in support of the chart series.
Collaboration Server (S-100): Concept within the S-100 framework allowing multiple producers to merge updates into a single product.
Compensation, Sound Velocity: Real-time correction of beam angles in a multibeam sonar using surface and through-water sound speed measurements.
Conductivity Cell: Sensor in a CTD that measures seawater conductivity, used to calculate salinity and sound speed.
Contour Interval: The vertical spacing between depth contours selected by a producer for an ENC cell.
CSAR (CARIS Spatial ARchive): Native gridded file format used by CARIS HIPS for managing high-density bathymetric data.
CTD: Conductivity-Temperature-Depth instrument, the standard hydrographic profiler.
CUBE (Combined Uncertainty and Bathymetry Estimator): Statistical algorithm by Brian Calder of CCOM that produces a depth surface and uncertainty grid from dense multibeam soundings, integrated into CARIS HIPS.

D

Datum Transformation: Conversion between different geodetic datums.
DBSV (Digital Bathymetric Survey Vessel): Generic term for purpose-built modern survey craft with integrated multibeam, INS, and acquisition software.
Deep Draft Survey: Survey designed to meet IHO S-44 Exclusive Order specifications for fairways used by commercial deep-draft vessels.
Dehradun (Indian Naval Hydrographic Office): Headquarters of the National Hydrographic Office of India at 107A Rajpur Road, Dehradun, established in 1954 and producing Indian INT charts and INENC cells.
Depth Curve: Charted contour of equal depth, also called isobath, typically drawn at standard values such as 5, 10, 20, 50, 100, 200, and 500 meters.
DGPS (Differential GPS): GPS augmentation using ground reference stations for corrections.
DHN (Diretoria de Hidrografia e Navegacao): Brazilian Navy hydrographic directorate in Niteroi, producing Brazilian charts under IHO standards.
dKart: An ENC production toolset family supporting S-57 producers worldwide.
DOLPHIN-MF: Autonomous surface vehicle used by SHOM and other agencies to extend nearshore hydrographic coverage.
DTM (Digital Terrain Model): Gridded depth or elevation surface, in hydrography typically resampled from CUBE or weighted-mean processing of multibeam soundings.
Dual-Head Multibeam: Configuration with two sonar heads angled outward to widen swath in shallow water, common on NOAA survey launches and harbor survey vessels.
Dynamic Draft Correction: Correction for vessel squat, settlement, and load changes applied to multibeam soundings to obtain true depth.

E

ECDIS (Electronic Chart Display and Information System): SOLAS-mandated electronic chart system.
Echosounder: Acoustic instrument that measures water depth.
EdgeTech 2205: Modular AUV-mounted side-scan and sub-bottom system from EdgeTech.
EdgeTech 4205: Tri-frequency towed sidescan sonar from EdgeTech with full spectrum chirp transmission.
EdgeTech 6205: Combined bathymetry and side-scan platform from EdgeTech delivering interferometric bathymetry alongside high-resolution imagery.
EM 122: Kongsberg deep water multibeam echo sounder operating at 12 kHz for full ocean depth bathymetric mapping.
EM 124: Kongsberg deep water multibeam echo sounder that succeeds the EM 122 with improved swath performance.
EM 2040: Kongsberg high-resolution shallow water multibeam echo sounder for inshore and coastal bathymetry.
EM 2040 MKII: Updated EM 2040 model with single, dual, or three-head options and enhanced bottom detection algorithms.
EM 304: Kongsberg full ocean depth multibeam echo sounder positioned between the EM 124 and the deeper EM 2040 family.
EM 710: Kongsberg shallow to mid water multibeam echo sounder operating at 70 to 100 kHz.
EM 712: Kongsberg medium water multibeam echo sounder used on survey vessels for shelf and slope mapping.
ENC Electronic Navigational Chart: S-57 and S-101 vector charts distributed via authorized services such as Primar and IC-ENC.
ENC Producer Code: The two-character country code and four-character agency code combination from IHO S-62.
EPSG: European Petroleum Survey Group registry of geodetic and projected coordinate reference systems, now maintained by IOGP, used universally in hydrographic software.

F

Feature Object Catalogue: Database of object classes and attributes in S-57 and S-101 used to encode chart features consistently.
FFI Fugro: Dutch geo-data company operating survey vessels and offering charting-grade hydrographic services to government and offshore clients.
Fish (Towed): Towed body housing a side-scan or sub-bottom transducer, kept at a target altitude above seabed by cable scope and vessel speed.
Fledermaus: Three-dimensional visualization software from QPS used to inspect bathymetric and water-column data from hydrographic surveys.
Fluid Mud: Soft, mobile near-bed layer detected by dual-frequency echosounders at 33 and 210 kilohertz, important for nautical depth definition in muddy ports.
FS Maria S Merian: German research vessel operated for the BMBF, conducting hydrographic and oceanographic missions worldwide.
FS Sonne: German research vessel commissioned in 2014, built at Meyer Werft, operated by Briese Schiffahrt under contract to BMBF for global deep-sea research with full-ocean multibeam coverage.
Full Coverage Survey: Hydrographic survey designed to ensonify 100 percent of the seabed using overlapping swaths, required under IHO S-44 Special and Exclusive Orders.

G

GEBCO (General Bathymetric Chart of the Oceans): Joint IHO and Intergovernmental Oceanographic Commission programme producing global bathymetric grids, with secretariat hosted at the British Oceanographic Data Centre.
GEBCO_2023 Grid: Global bathymetric grid at 15 arc-second resolution combining multibeam, single-beam, and satellite-derived data, the current public reference product.
Geodesy: Science of measuring Earth's shape, gravity, and rotation.
GeoTIFF: Tagged Image File Format with embedded geospatial metadata, commonly used to deliver bathymetric surfaces and backscatter mosaics.
GHEOS: General Hydrographic Equipment Office Standard, an internal procurement reference used by several navy hydrographic services.
Global Sea Mineral Resources: Belgian deep-sea exploration company that has conducted hydrographic surveys in the Clarion-Clipperton Zone.
GMDSS Master Plan: IMO circular GMDSS.1 listing recognized stations and services worldwide.
GNSS-derived Vertical Reference Surface: Ellipsoid-referenced separation surface relating GNSS heights to chart datum, key to GNSS tide methods in hydrographic survey.
Gravity Tie: Survey procedure connecting absolute gravity to local stations, supporting geoid and ellipsoid-to-chart-datum modeling.

H

Hardware Time Sync: Use of PPS pulses and ZDA strings from a survey GNSS to discipline sonar and INS time, eliminating processing latency biases.
Heave: Vertical translational motion.
HELCOM Hydrographic Re-survey Scheme: Coordinated Baltic Sea hydrographic survey programme run by Helsinki Commission member states to bring shipping routes to modern survey standards.
HIPP (Harbor Imagery and Photogrammetry Project): NOAA survey project using lidar and photogrammetry for shoreline mapping along the US coast.
HMS Echo: Royal Navy Echo-class survey vessel pennant H87, built by Appledore Shipbuilders in 2002 and commissioned in 2003, equipped with EM 710 multibeam.
HMS Enterprise: Royal Navy Echo-class survey vessel pennant H88, sister to HMS Echo, commissioned in 2003 for global hydrographic operations.
HMS Magpie (H130): Royal Navy coastal survey vessel commissioned in 2018, built by SeaQuest Systems in Cork, used for inshore hydrographic survey in UK waters.
HMS Protector: Royal Navy ice patrol ship that conducts incidental hydrographic survey in Antarctic waters in support of UKHO charting.
Holland-Linotype Sweep: Historical mechanical sweep used to verify clear depths over channels before single-beam echosounders matured.
HOOK (Hydrographic Office Operations Kit): Internal toolset used at UKHO for distributing product updates.
Horizon Sonar: Klein Marine Systems towed side-scan model used by smaller survey vessels and naval mine countermeasures forces.
Hostile Environment Survey: Operations in ice, high-current, or piracy-prone areas, often using autonomous or unmanned systems coordinated with hydrographic offices.
HSL (Hydrographic Survey Launch): Generic class of survey launches typically 8 to 12 meters long with integrated multibeam, used as ship's boats on mother survey vessels.
HSSD (Hydrographic Survey Specifications and Deliverables): NOAA OCS document detailing survey accuracy, processing, and deliverable requirements for contract and in-house surveys.

I

ICCM (Integrated Coastal and Marine Mapping): Multi-agency programme combining bathymetry, topobathy lidar, and habitat mapping in coastal zones.
IHO Capacity Building Programme: IHO initiative supporting hydrographic capability development in coastal states, funded partly by the Nippon Foundation.
IHO Council: The intergovernmental body advising on IHO programme priorities between Assemblies.
IHO Member State: A national government acceded to the IHO Convention; over 100 states as of 2024.
IHO Monaco Headquarters: International Hydrographic Organization secretariat located at 4 quai Antoine 1er, Monaco, established at the founding of the IHB in 1921.
IHO S-100: Universal Hydrographic Data Model.
IHO S-101: Next-generation ENC specification.
IHO S-102: Bathymetric Surface product specification.
IHO S-104: Water Level Information product spec.
IHO S-111: Surface Currents product spec.
IHO S-122 to S-129: Family of S-100 product specifications covering marine protected areas, marine traffic management, nautical publications, ice information, marine physical environment, navigational warnings…
IHO S-23: IHO publication Limits of Oceans and Seas, the canonical reference to named ocean and sea boundaries, last full edition issued in 1953 with a draft fourth edition pending.
IHO S-4: Regulations for International (INT) Charts and Chart Specifications of the IHO.
IHO S-44: IHO standard for hydrographic surveys, defining order categories.
IHO S-52: Specifications for chart content and display aspects of ECDIS.
IHO S-57: ENC product specification, edition 3.1.
IHO S-63: Data Protection Scheme for encrypted ENCs.
IHO Secretary-General: Chief executive officer of the IHO Secretariat in Monaco, supported by two Directors elected by the Assembly.
IHO World Hydrography Day: Annual observance on 21 June commemorating the establishment of the International Hydrographic Bureau in 1921.
IIC Technologies: A Canadian-headquartered hydrographic services and ENC production company.
INENC: Indian Electronic Navigational Charts produced by the Indian Naval Hydrographic Office in Dehradun and distributed via several international ENC services.
Innomar SES-2000 Compact: Parametric sub-bottom profiler from Innomar producing narrow beam, high-resolution profiles in shallow waters down to about 1 meter resolution.
Innomar SES-2000 Deep: Deepwater variant of Innomar's parametric sub-bottom profiler series, used down to several thousand meters.
Innomar SES-2000 Medium: Mid-range parametric sub-bottom profiler used on coastal and harbor surveys.
Inshore Survey Boat: Small craft, typically under 8 meters, fitted with shallow-water multibeam and INS, used in marinas and ports.
INSPIRE Directive: European Union directive requiring harmonized spatial data, applicable to hydrographic data products served by national hydrographic offices.
Integrated Navigation System: Tightly coupled GNSS and INS providing position, attitude, and heading at survey-grade accuracy on hydrographic vessels.
International Charts (INT): Common-format charts compiled to IHO INT scheme, with numbering coordinated by regional hydrographic commissions.
International Hydrographic Review (IHR): Open-access journal of the IHO publishing hydrographic and cartographic research.
IOC (Intergovernmental Oceanographic Commission): UNESCO body partnering with IHO on GEBCO and other ocean mapping programmes.
IXBlue Hydrins: Inertial unit from iXblue tailored for hydrographic survey, with integrated GNSS aiding.
IXBlue Marins M11: Strapdown FOG INS used on naval and survey ships for primary navigation with hydrographic-grade precision.
iXblue PHINS: Subsea inertial navigation system from Exail, formerly iXblue, widely used on AUVs and work-class ROVs.

J

JCG Survey Vessel Takuyo: Japan Coast Guard hydrographic survey ship operated by JHOD for offshore mapping under IHO standards.
JCOMM (Joint WMO-IOC Commission for Oceanography and Marine Meteorology): Joint body whose remit included integrated ocean services, partially aligned with hydrographic needs before being restructured.
JHOD (Japan Hydrographic and Oceanographic Department): Hydrographic agency of the Japan Coast Guard, based in Tokyo, founded in 1871 and producing Japanese paper and electronic charts.
JHOD R/V Heiyo: Japan Coast Guard hydrographic survey ship, also operated by JHOD for coastal and EEZ surveys.
JHOD R/V Shoyo: Japan Coast Guard hydrographic survey ship operated by JHOD.
JOIDES Resolution: Drilling vessel of the International Ocean Discovery Programme, used for scientific drilling rather than hydrographic charting but contributing seabed geological context.

K

K-Controller: Kongsberg acquisition and control software for EM-series multibeam echosounders, replacing the legacy SIS interface on newer installations.
Kalman Filter, INS: Recursive estimator combining GNSS positions and inertial measurements to produce a smooth, drift-corrected navigation solution on survey vessels.
Kappa Coefficient (Beam): Sonar parameter relating beam angle to effective ground footprint, used in performance calculations.
Kavraisky Projection: Conformal projection occasionally used on Russian and ex-Soviet charts at specific scales.
Kelvin Hughes SharpEye: Civil and naval radar series widely fitted to hydrographic survey vessels for navigation.
Klein 3900: High-resolution dual-frequency side-scan sonar from Klein Marine Systems operating typically at 445 and 900 kilohertz.
Klein 4900: Combined side-scan and bathymetry system from Klein.
Klein 5000 V2: Multi-beam side-scan sonar offering increased resolution at speed, used for naval and survey applications.
Klein 5900: Multi-beam side-scan sonar from Klein with along-track beamforming for high-resolution imagery of small targets such as mines.
Knudsen 3200: Dual-frequency chirp echosounder and sub-bottom profiler from Knudsen Engineering used on survey and research vessels.
Knudsen Pinger SBP: Sub-bottom profiler line from Knudsen using low-frequency pinger sources for deeper penetration.
Kongsberg Hugin: Autonomous underwater vehicle family used for deepwater survey, owned by hydrographic and oil-and-gas operators including Fugro and DOF.
Kongsberg Maritime: Norwegian supplier of bridge, automation and dynamic positioning systems.

L

LADS Mk3: Australian airborne lidar bathymetry system developed for the Royal Australian Navy, supporting AHO charting of shallow tropical waters.
Latitude Geodetic: Angular coordinate measured from the equator along the meridian to the point on the reference ellipsoid, fundamental to chart construction.
Leadline: Pre-electronic depth-measurement tool consisting of a marked rope and weighted lead, occasionally still carried for backup checks.
LIDAR (Light Detection and Ranging): Laser ranging technique used for shoreline mapping and shallow bathymetry, central to topobathy products from NOAA and others.
Light sector: Arc through which a sectored light shows a particular color.
Local Plotting Sheet: Hydrographic working chart at survey scale used in the field to plan and monitor coverage.
Lowest Astronomical Tide (LAT): Lowest tide level predicted to occur under average meteorological conditions, the standard IHO chart datum.

M

MapInfo Discover: GIS tool occasionally used by hydrographic offices for thematic chart compilation.
MARIS: Norwegian ECDIS manufacturer producing systems used on offshore and survey vessels.
MBES (Multibeam Echosounder): Acoustic sonar that ensonifies a fan of beams across the vessel track to produce a swath of depth measurements per ping.
Minehunter Survey: Naval task in which hydrographic-grade sonars classify seabed objects to detect mines, often using Klein 5000 or Kongsberg HUGIN AUVs.
Mooring Survey: An inspection of mooring lines, fairleads, bitts, and winches under OCIMF Mooring Equipment Guidelines for tanker terminal acceptance.
MSDI (Marine Spatial Data Infrastructure): Framework of standards and services for sharing marine geospatial data, promoted by the IHO Marine SDI Working Group.
Multibeam Backscatter: Acoustic intensity of seabed return per beam, processed into mosaics for seabed classification alongside bathymetry.
Multibeam Snippet: Time series of return amplitude across the bottom-detection footprint of a single beam, used for higher-fidelity backscatter products.
Mutual Recognition: IHO arrangement under which hydrographic offices accept each other's ENCs as equivalent for SOLAS purposes within the AVCS and Primar services.

N

NAUTHIS: French hydrographic information system maintained by SHOM for chart production.
Nautical mile: 1852 m international nautical mile.
Nautical Publications (S-128 and ADMIRALTY): Reference documents complementing charts, including catalogs, light lists, tide tables, and sailing directions.
NAVAREA Coordinator: National authority responsible for issuing NAVAREA warnings in its area.
Navigation Warning: Time-critical message about hazards to navigation, broadcast via NAVTEX and SafetyNET and incorporated into ENC update workflows.
NHS Stavanger: Norwegian Hydrographic Service headquarters at Lervigsveien 36, Stavanger, part of the Norwegian Mapping Authority Kartverket.
Nippon Foundation-GEBCO Seabed 2030: Joint programme between the Nippon Foundation and GEBCO launched in 2017 to map the entire ocean floor by 2030.
NIPR (National Institute of Polar Research, Japan): Operator of the Japanese icebreaker Shirase, which conducts incidental hydrographic survey in Antarctic waters.
NIPWG (Nautical Information Provision Working Group): IHO working group developing S-100-based product specifications for nautical publications.
NMEA 0183 and 2000: Marine electronics communication standards used to exchange position, attitude, and depth data between sensors and acquisition software on survey vessels.
NOAA Atlantic Hydrographic Branch: NOAA OCS field branch in Norfolk, Virginia, supporting east coast and Gulf of Mexico hydrographic survey operations.
NOAA Custom Chart: NCC, a NOAA service producing user-defined PDF chart areas derived from US ENCs after the sunset of legacy paper charts.
NOAA ENC Direct: Public website distributing US ENC cells freely under NOAA's open-data policy.
NOAA Marine Chart Division: Division within NOAA OCS responsible for compiling, maintaining, and publishing US ENCs and paper charts.
NOAA Office of Coast Survey: OCS, the US federal hydrographic office, descendant of the 1807 Survey of the Coast.
NOAA Pacific Hydrographic Branch: NOAA OCS field branch in Seattle, Washington, supporting west coast and Alaskan hydrographic survey operations.
NOAA Ship Fairweather (S 220): NOAA hydrographic survey ship homeported in Ketchikan, Alaska, built in 1968 by Aerojet General, performing multibeam surveys of Alaskan waters.
NOAA Ship Rainier (S 221): NOAA hydrographic survey ship homeported in Newport, Oregon, built in 1968 by Aerojet General, conducting multibeam surveys along the US west coast and Alaska.
NOAA Ship Thomas Jefferson (S 222): NOAA hydrographic survey ship homeported in Norfolk, Virginia, originally built as USNS Littlehales in 1991 and transferred to NOAA in 2003.

O

Object Class (S-57): Defined feature type such as DEPARE, COALNE, or LIGHTS, encoded in ENC cells with attributes from the IHO S-57 catalogue.
OCEAN INFINITY: Marine robotics company operating Armada-class uncrewed survey vessels for hydrographic and seabed mapping projects.
Oceanographic Cast: Lowering of a CTD or sound velocity profiler to obtain a water column profile in support of multibeam corrections.
OEM Sonar: Sonar electronics packaged for integration into third-party platforms, common in AUV and ASV installations.
Open Navigation Surface: Industry-led format effort that produced the BAG file structure, now stewarded by the OpenNavigationSurface working group.
OpenCPN: An open-source chart plotting software supporting unencrypted ENC display.
OPENS-100 Forum: Industry forum promoting interoperability of S-100 product specifications.
Operational Capability Vessel (OCV): Class of survey ships emphasizing mission flexibility through containerized payloads and modular sensor frames.
Orthometric Height: Height above the geoid, derived from ellipsoidal GNSS height using a geoid model in vertical-datum workflows.

P

Pacific Marine Energy Centre: Test site whose seabed has been mapped multiple times to track infrastructure impacts using NOAA-style hydrographic methods.
Pan Geo Subsea: Service company offering 3D acoustic imaging for offshore site investigations.
Paper Chart Service (PCS): UKHO programme distributing weekly Notices to Mariners updates for paper ADMIRALTY charts.
Patch test: Trial application of a coating to confirm adhesion and behavior before full-scale work.
PDS2000: Teledyne RESON hydrographic acquisition and processing software, used widely on smaller survey craft.
Pelagia: NIOZ research vessel based at Texel that has contributed to North Sea hydrographic studies.
PHINS Subsea: iXblue inertial unit packaged for subsea use on ROVs and AUVs supporting hydrographic survey.
Pinger: Acoustic device used in fisheries and observations.
Pinger Localization: Acoustic positioning of subsea assets by transponder, often integrated with hydrographic survey workflows.
Pourquoi Pas?: French research vessel commissioned in 2005, operated jointly by Ifremer and SHOM, equipped with EM 122, EM 710, and SBP 120 sub-bottom profiler.
Pourquoi Pas? IV: Historic reference to the lineage of vessels named for Jean-Baptiste Charcot's polar exploration ship Pourquoi Pas?.
PPK (Post-Processed Kinematic): GNSS processing technique used to deliver centimeter-level positions after a survey, supporting GNSS-tide workflows.
Primar: The Norwegian RENC based in Stavanger, distributing ENCs from member HOs worldwide.
Product Specification (S-100): Document defining the content, structure, and encoding of an S-100 product such as S-101 or S-102.
Profile, Sound Velocity: Vertical profile of sound speed used to refract beam paths in multibeam processing.
Push-broom Lidar: Topobathy lidar configuration projecting a fixed line of laser shots, typical of certain hydrographic airborne sensors.

Q

Qarto: QPS application for compiling S-57 and S-101 ENC cells from validated hydrographic data.
QC, Hydrographic: Quality control procedures applied to soundings, side-scan imagery, and metadata before submission to a hydrographic office.
QGIS: Open-source GIS used for visualization of hydrographic data, supported by plugins such as the Qgis BAG reader.
Qimera: QPS post-processing application focused on multibeam cleaning and surface generation.
QINSy: QPS hydrographic acquisition and online processing software used on a large fraction of commercial survey craft.
QPS (Quality Positioning Services): Dutch software company in Zeist producing QINSy, Qimera, Qarto, and Fledermaus for hydrographic workflows.
Quality of Bathymetric Data (QoBD): Metadata in S-101 conveying source survey accuracy, replacing the older Zones of Confidence concept.

R

R2Sonic 2024: R2Sonic ultra-wideband multibeam echo sounder for survey and offshore applications.
R2Sonic 2026: High-frequency variant of the R2Sonic 2024 with extended angular coverage.
R2Sonic 2030: Deepwater variant of the R2Sonic family operating at lower frequencies for greater depth coverage.
R2Sonic Truepix: Backscatter snippet processing technology in R2Sonic systems for higher-fidelity seabed imagery.
Raster Nautical Chart (RNC): Digital scan of a paper chart, distributed historically by NOAA and UKHO and now being retired in favor of vector ENCs.