Shom is the national referent for the level of the sea in situ on all areas under French jurisdiction. In this capacity, he assures under the acronym REFMAR different coordination functions in the collection and dissemination of public data related to water level observations, in order to promote their use in multiple applications within the framework of international recommendations.

The georeferenced digital image solution for the nautical chart is a digital conversion of the corresponding printed nautical chart produced by Shom or its legends, with georeferencing indications and including miscellaneous text.

Weather forecasting models are used to show atmospheric conditions by computing changes in meteorological parameters on a 3D atmospheric grid model. Physical laws are used to determine behaviour: fluid mechanics, variation in water phase, turbulence, radiation, and atmospheric interaction with space, the continents and the oceans. The initial conditions are determined by assimilating variational data including a large volume and wide variety of in situ observations obtained from remote detection systems. The weather forecasts available on data.shom.fr only contain "wind at 10m" and "atmospheric pressure at sea level" parameters. A land/sea mask is then applied to exclude non-maritime forecasts. These forecasts are taken from 2 different types of models: ARPEGE for world and European scale input (0.5° to 0.1° resolution) and AROME for mainland France (1.3 km resolution). ARPEGE is a global hydrostatic spectral model, with variable horizontal resolution (centred on France), vertical finite element modelling and hybrid vertical coordinates. ARPEGE is an integral part of the Arpège-IFS software package, designed, developed and maintained by Météo-France in cooperation with ECMWF (European Centre for Medium-Range Weather Forecasts - http://www.ecmwf.int/). AROME is a non-hydrostatic spectral model for weather forecasts in mainland France, with finite difference modelling for vertical input and hybrid coordinates. AROME was developed by Météo-France thanks to close national (CNRS) and international (CEPMMT, Aladin, Hirlam) cooperation programmes on the basis of the Méso-NH research model and the dynamic core of the Aladin model.

These maps are prepared on the basis of vector-based mapping data (IHO S-57 format) including the detailed description of each object (beacons, wrecks, submarine cables, regulated zones, survey systems, etc.). These maps are the digital equivalent of printed nautical charts.

French Ministry of Agriculture and Food / DRASSM - Shom<br /> The product "Limits related to fishery uses" contains the limits related to fishery uses as defined in the French or European legislations. Those limits are managed by the Directorate for Sea Fisheries and Aquaculture (DPMA) of the Ministry of Agriculture and Food. <br /> Those limits are divided into three categories : <br /> - the inner limit of the coastal waters (6 nautical miles) ; <br /> - the 3-nautical-mile limit ; <br /> - the limit of fisheries for overseas territories (100 nautical miles).<br /><br /> The product "Limits related to fishery uses" is to use in addition to the digital product “Maritime Limits and Boundaries” of Shom (French: “Délimitations maritimes”) which represents the limits of the French maritime spaces of sovereignty or jurisdiction through the World.<br /> The product “Maritime Limits and Boundaries” (French: “Délimitations maritimes”) can be viewed and downloaded on the French national portal of maritime limits (https://maritimelimits.gouv.fr).

Shom manages a network of permanent digital coastal tide-gauges on French coasts: the RONIM Sea Level Observation Network. Most tide-gauge observatories are partnered with one or more local partners.<br /><br /> Four main types of data are available for download:<br /> - “Raw high frequency" data: raw observations neither validated nor evaluated, obtained directly from the sensor. 1-minute measurement; integration time 15 seconds (on the minute); sampling period: 1 second.<br /><br /> - "Raw non-real time" data: raw observations neither validated nor evaluated, obtained directly from the sensor. 10-minute measurement; integration time 121 seconds (around every 10 minutes); sampling period: 1 second.<br /><br /> - "Validated non-real time" data: observations checked and validated by Shom from the "Raw non-real time" data. 10-minute measurement; integration time 121 seconds (around every 10 minutes); sampling period: 1 second.<br /><br /> - "Validated hourly" data: observations checked and validated by Shom, generated from "Validated non-real time" data. Hourly measurement obtained from the Vondrak filter with triangular weighting. The hourly height cannot be calculated in the event of an observation gap greater than 1.5 hours.

Non-georeferenced digital images in JPEG2000 format from former hydrographical survey fair sheets obtained from Shom's historical archives.

French Ministry of Culture / DRASSM – Shom The product "Limit of preventive archeology licence fee" contains the limits for the preventive archeology licence fee (1 nautical mile) as defined in the French Heritage Code. This limit is managed by the Department of Underwater Archeological Research (DRASSM) of the Ministry of Culture. This limit, defined by the Heritage Code at 1 nautical mile from the low-water line, permits to delineate the areas where the licence fee for preventive archeology at sea is applied. In Mainland France in the Gironde estuary, the limit for the preventive archeology licence fee is stopped by the crosswise limit of the sea as defined by the decree of 26 August 1857. In French Guiana, the limit for the preventive archeology licence fee is stopped in Maroni and Oyapock rivers by the crosswise limits of the sea respectively defined the order of 30 January 1991 and the order No 863 of 26 May 1986, until meeting the land boundary which delineates the rivers with the neighbouring States. The product "Limit of preventive archeology licence fee" is to use in addition to the digital product “Maritime Limits and Boundaries” of Shom (French: “Délimitations maritimes”) which represents the limits of the French maritime spaces of sovereignty or jurisdiction through the World. The product “Maritime Limits and Boundaries” (French: “Délimitations maritimes”) can be viewed on data.shom.fr (Maritime boundaries Category) and downloaded on the French national portal of maritime limits (https://maritimelimits.gouv.fr).