Glossary of Terms

A quick reference guide to some of the terms used

Wondering what we mean by Data Management? Do you know what the term MSDI means? Please find below a short glossary of the terms used on our website. If you spot any not included here and you’d like us to add it – please email us at

For terminology and references for our mapping products please visit our Mapping Feature Catalogue.

Data Management is the development, execution and supervision of plans, policies, programmes and practices that control, protect, deliver and enhance the value of data and information assets. Data is now widely considered to be the second most valuable asset an organisation possesses after its employees. With data volumes multiplying every few months, it is critically important that organisations value and manage his asset through its life-cycle including its collection, quality assurance, quality, ingestion, curation, archiving and use.
Resource links:
Dama (The Global Data Management Community)
MEDIN (Marine Environmental Data and Information Network)

Want to know more? Why not download our white paper “Why Data Management Matters to Ports and Harbours” or see our press article.

Data Governance is the execution and enforcement of authority over the management of data and data-related resources.

See the interesting article on this subject here by Nicola Askham (an Independent Data Governance Coach).

A Spatial Data Infrastructure is the relevant base collection of technologies, policies and institutional arrangements that facilitate the availability of and access to spatial and business data. It covers the processes that integrate technologies, policies, standards, and people; the structure of working practices and relationships across data producers and users for access, sharing and analysing geospatial information across government and commerce. It also includes hardware, software and system components necessary to support the processes. Importantly, an SDI is not a central repository for data, a portal for discovery, view and download of data nor simply GIS software.

A Marine Spatial Data Infrastructure encompasses all marine and / or maritime information including maritime boundaries and limits, conservation areas and marine habitats, oceanography, bathymetry, geology, wrecks, offshore installations, pipelines and cables.

Please download our MSDI white paper or see our press article here.

A Maritime Information Infrastructure (MII) is based on good data management principles and applies lean process management from manufacturing to the flow of information through the port. It is built on the “four cornerstones” of a Spatial Data Infrastructure (see above) and applies these at the enterprise level. It involves engaging and educating port personnel and contractors (people), applying open system and technical standards, utilising existing, or where required, improving ICT infrastructure, introducing registries and metadata, and strengthening data. See our full press article here on “Delivering a Maritime Information Infrastructure to Ports” and MII diagram.
ENC stands for ‘Electronic Navigational Chart’.
If you require ENC’s, OceanWise can provide several options. We offer: an ENC Web Map Service, software that allows you to produce your owns ENCs or if you don’t have access to a GIS, we can create ENC’s for your specific needs. Please click here.

Telemetry is the process of recording and transmitting the readings of an instrument OR “the mechanism of getting data from where its collected to where it is needed”. OceanWise specialises in marine telemetry handling the process of recording and transmitting the readings of marine sensors and equipment such as weather and tidal data, so that it can be viewed, used and disseminated by those who need it (for example VTS teams, Pilots, Dredgers, Hydrographers etc).
We use the term ‘Smart Telemetry’ to describe our specially developed modems (rt.buffer and ip.buffer) which are deemed as “smart” because of their extra attributes which are: configurable, swift, intelligent, compact, flexible, robust, secure, remotely managed, power & cost efficient. Download our brochure here.
The UN-MGIWG stands for the UN Marine Geospatial Information Working Group. See our full press article here.
The UN Marine Geospatial Information Working Group (UN-GGIM). See our full press article here. Please also see the article in GIS Professional June 2019 on the difference between OGC, GEO and UN-GGIM & “Driving the Global Geospatial Agenda
The XL stands for eXcluding Land
Land mapping datasets tend to fill bodies of water with a shade of blue, because maritime information isn’t useful for the majority of their users. In the same vein, Nautical Charts fill land with a mustard shade. These datasets are suitable for someone navigating a car, or a ship, but what happens when your use case requires harmonised land and maritime information? RCXL is developed to solve this exact issue.
By removing the land from Nautical Charts, users are now able to combine the useful aspects of both datasets for a harmonious mapping experience across land and sea. Finally, as Nautical Charts are designed without any context of the surrounding charts, land from one chart will often overlap valid maritime data from another – a by-product of removing the land is that issue is also resolved in RCXL.

Our mapping data is available in digital form as either a Raster Chart in Geotiff format or in various GIS friendly vector formats e.g. GML, SHP, FGDB.
Raster Charts are simply digital images of standard nautical paper charts. This means that they only show the information available on the paper chart. Each pixel in the image represents a colour value so there is no intelligence in the raster image. Raster charts are created by scanning the paper chart.

Marine Themes Vector is an intelligent dataset. It is coded with additional information not available in paper or raster charts. It carries a wealth of geo-spatial data and is linked to a database of associated information. The user can click on different features, such as a shipwreck or buoy, and retrieve additional information about that specific feature. For example, a wreck appears only as an symbol on an raster chart, but in the vector data a user can click on the feature and see the additional information, such as depth, date sunk and cargo. Marine Themes Vector also provides the user with control over how the chart is displayed, so you can easily turn different layers of information on and off leaving you with a tailored map only showing the user the details that they require. Try our range of mapping products out for yourself on our demo page: Or download our data buying guide here.

At OceanWise we believe that it is of utmost importance that systems are fully tested and proved fit for purpose. As part of our standard process we invite our customers to attend a FAT – this is where the customer(s) are invited to our workshop to observe the system working as specified. A User Acceptance Test (UAT) is the same but usually undertaken post deployment, on site with the end users, again the purpose of this is to prove that the system is working as specified.
Bathymetry is the study of mapping the seafloor. See Hydro International’s September 2019 article on what bathymetry is here.
A Digital Elevation Model is a representation of the Earth’s surface. It is a grid of squares where each square represents the height/depth at that location. Our Marine Themes Digital Elevation Model represents the depth of water (relative to Chart Datum) so shows the shape of the seabed.
Shoal Bias is the practice of taking the shallowest depth in an area to show on a navigational chart to ensure safe navigation. The depths on a navigational chart do not necessarily accurately represent the true form of the seabed. If you are interested in the true form of the seabed, our Marine Themes Digital Elevation Model is derived from high accuracy survey data and does not have shoal bias applied.
A bathymetric chart differs from a hydrographic chart in that accurate presentation of the underwater features is the goal while safe navigation is the requirement for the hydrographic chart. A hydrographic chart will obscure the actual features to present a simplified version to aid mariners in avoiding underwater hazards.