The purpose of Sextant is to collect reference data relating to the marine environment and make it available via a catalogue. Sextant provides support for environmental issues such as biodiversity, renewable marine energies, integrated coastal zone management, fisheries, shoreline and deep-sea environments, and seabed exploration and exploitation. 

The geographical data available via Sextant is obtained through research and scientific programmes run by Ifremer's research units and partners. It includes various types of data:

• satellite, aerial, hyperspectral and acoustic imagery
• the physical environment: bathymetry, sedimentology, morphology, hydrodynamics, climatology
• the biological environment: remarkable habitats, benthic populations, marine mammals, fishery resources, biogeochemistry, microbiology
• human uses and activities: professional fisheries, aquaculture, maritime navigation, tourism and pleasure boating, surveillance networks
• regulatory data: Natura 2000 areas, ZNIEFF, OSPAR, etc.
• administrative sea boundaries: Exclusive Economic Zones (EEZs), FAO areas, ICES statistical rectangles, etc.

Sextant complies with ISO and OGC standards and is an interoperable system which enables geographical data exchanges with most French government organisations and services, with the institute's many scientific partners (IRD, AAMP, MNHN, the French coastal protection agency, universities (CNRS)) as well as with the major data producers IGN, SHOM and BRGM[SF1] .

Sextant therefore responds to the needs of different projects at scales ranging from regional (Rebent, Medbenth, Pelagis, etc.), to national (MSFD, marine granulates, WFD, etc.) to international (EMODnet, Copernicus Marine Core Services, SeaDataNet, etc). The geographical data available via Sextant is obtained through research and scientific programmes run by Ifremer's research units and partners. It includes various types of data: bathymetric, geological, hydrological, biological, economic and regulatory aspects of the marine environment. This thematic data is approved and finalised, and certain datasets constitute reference data.

In late 2015, Sextant included 116 thematic catalogues comprising 6950 metadata entries. Of these 6950 entries, 4790 were accessible to the general public and represented 7000 geographic layers.