The Tidal stream atlas netcdf product – Northern Brittany provides tidal current data for an area stretching from Tregastel at the east of the area to Porsguen at the west. The product consists of two gridded files with different spatial resolutions covering the Northern Brittany area (overall view at 500 m) and the geographical area of the port of Roscoff (250 m). The U and V velocities of the tidal currents depend on the tidal conditions considered at mean neap and spring tidal rates. The data are provided in m/s for the surface layer. The times are given in relation to high tide at the reference port chosen in the area and are provided from 6 hours before to 6 hours after that reference.

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.

Litto3D is a unique and continuous land-sea database which can provide 3D models of the shape and location of French coastal terrain. A line separates sea and land data acquisition zones, and the associated survey readings obtained using bathymetric lidar technologies or multibeam echosounders for sea readings and airborne lidar topographical surveys for land readings, with 300 m overlap. Litto3D digital models are available in two formats: a set of 3D points and a qualified terrain mesh.

The "Military practice areas" product contains vector data in the form of 2D surface objects describing the military practice areas in the France sector represented on Zonex variants of nautical charts. This is the S-57 MIPARE object class (military practice areas): maritime zone within which military, naval or air exercises can take place.

<em>Surface current predictions computed from statistical values obtained from the IROISE 3D 2011 Telemac hydrodynamic model gridded with a regular 30m spatial resolution.</em><br /> <br /> This service offers a visualization of surface current predictions computed from statistical values obtained from a high resolution hydrodynamic simulation at mean Neap and Spring corresponding to a tide coefficient of respectively 45 and 95. Those statistics are then interpolated/extrapolated every 15 minutes (cubic spline), and for each tide coefficient from 20 to 120 (linear). The statistical currents, initially referenced to Brest high tide, are then referenced to the hour requested by the user using the tide prediction service <a href="http://maree.shom.fr" target="_blank">http://maree.shom.fr</a>. This service was built by Shom and funded by French CCI Métropolitaine Bretagne Ouest (<a href="https://www.bretagne-ouest.cci.bzh/" target="_blank">CCIMBO</a>) in the frame of the <a href="https://www.atlanticblueports.com" target="_blank">Atlantic Blue Port</a> project of <a href="http://www.atlanticarea.eu" target="_blank">Interreg Atlantic Area</a> european program.<br />

The Tidal stream atlas netcdf product – Northern Brittany provides tidal current data for an area stretching from Tregastel at the east of the area to Porsguen at the west. The product consists of two gridded files with different spatial resolutions covering the Northern Brittany area (overall view at 500 m) and the geographical area of the port of Roscoff (250 m). The U and V velocities of the tidal currents depend on the tidal conditions considered at mean neap and spring tidal rates. The data are provided in m/s for the surface layer. The times are given in relation to high tide at the reference port chosen in the area and are provided from 6 hours before to 6 hours after that reference.

Litto3D Marine Part is an intermediate product of the Litto3D product containing only marine data.Litto3D is a unique and continuous land-sea database which can provide 3D models of the shape and location of French coastal terrain. A line separates sea and land data acquisition zones, and the associated survey readings obtained using bathymetric lidar technologies or multibeam echosounders for sea readings and airborne lidar topographical surveys for land readings, with 300 m overlap. Litto3D digital models are available in two formats: a set of 3D points and a qualified terrain mesh.

Bathymetric datasets are an extraction of surveys belonging to the Shom public database. For depth up to 50m, the vertical precision of soundings varies from 30cm to 1m and the horizontal precision varies from 1 to 20m. In deep ocean, the vertical precision is mainly around 1 or 2% of the bottom depth. It is sometimes more, it depends on the technology used. The data are referenced to ZH which is assimilated to LAT. Data are corrected for sound velocity variations. <br /> October 27 2025 version

Litto3D Marine Part is an intermediate product of the Litto3D product containing only marine data.Litto3D is a unique and continuous land-sea database which can provide 3D models of the shape and location of French coastal terrain. A line separates sea and land data acquisition zones, and the associated survey readings obtained using bathymetric lidar technologies or multibeam echosounders for sea readings and airborne lidar topographical surveys for land readings, with 300 m overlap. Litto3D digital models are available in two formats: a set of 3D points and a qualified terrain mesh.

"Traffic Separation Schemes" product contains a description of TSS in French maritime spaces. A TSS is a routeing measure aimed at the separation of opposing streams of traffic by appropriate means and notably by the establishment of traffic lanes. The measures taken aim at improving navigation safety in areas where navigation is threatened by the density of traffic associated with various natural difficulties. Several classes of objects constitute this product, the acronyms used are those of IHO standard S-57: - Traffic separation scheme lane part (TSSLPT): area of a traffic lane in which the direction of flow of traffic is uniform; - Traffic separation scheme boundary (TSSBND): outer limit of a traffic lane part or a traffic separation scheme roundabout; - Traffic separation line (TSELNE): common boundary between two traffic lanes, or between one traffic lane and one inshore traffic zone; - Traffic separation zone (TSEZNE): separation areas between two traffic lanes, or between one traffic lane and one inshore traffic zone, or to the central area of a roundabout; - Inshore traffic zone (ISTZNE): area between the landward boundary of a traffic separation scheme and the adjacent coast; - Precautionary area (PRCARE): area, within defined limits, where ships must navigate with particular caution, and within which the direction of traffic flow may be recommended; - Deep water route part (DWRTPT): sections within which the flow of traffic either follows one defined direction for one-way traffic, or follows one defined direction and its reciprocal for two-way traffic. A deep-water route is a route in a designated area within defined limits which has been accurately surveyed for clearance of sea bottom and submerged obstacles to a minimum indicated depth of water; - Two-way route part (TWRTPT): sections within which traffic flows in two directions along one bearing and its reciprocal. These route parts are generally two-way, but some may be restricted to one-way traffic flow; - Radio calling-in line (RDOCAL_lne) : positions at which vessels are required to report to a traffic control centre.