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.

The land-sea limit corresponds to the Highest Astronomical Tide (HAT) in the case of a tide of coefficient 120 and under normal meteorological conditions (no offshore wind and mean atmospheric pressure of 1013 hPa). This geometric line is naturally defined as the intersection of a HAT model (extended to the coast and the top end of the upper estuary) based on the available Bathyelli surfaces, and a high-resolution digital terrain model of the coastal area. It corresponds to the highest limit of the intertidal area and takes into account, when they exist, the 3 administrative maritime limits which are: the transversal limit of the sea (LTM), the salt water limit (LSE) and the limit of maritime jurisdiction (LAM). This limit is measured (quoted) in relation to the local hydrographic chart datum and to the levels of reference for France (IGN69 and IGN78 for Corsica). Relations to other levels of reference (mean sea level and ellipsoid) are known. The land-sea limit product, mainly results from the exploitation of the two products Litto3D®/RGEALTI® and Bathyelli, and represents, with a metric resolution (1 to 5 metres), this theoretical entity by a set of 2D polylines describing the nature of the coast (artificial or natural, rocky or sandy, steep or flat, etc.). The method used for calculating the land-sea limit makes it possible to produce a continuous, homogeneous and spatially coherent limit on the entire French metropolitan coastal area.

The product "Distribution of the submarine dunes of the French continental shelf" contains digital vector data provided as 2D linear objects representing the crest of submarine dunes digitized from bathymetric surveys conducted by the Shom. When several surveys have been carried out on the same area or dune, the product contains the information from all the surveys. However, the data displayed on data.shom.fr is limited to the information from the most recent survey.

The product "BathyElli surfaces v2.1" contains the surface realisation of the ellipsoidal height at the reference date of 1 January 2000 of the characteristic tidal levels corresponding to : - Highest Astronomical Tide (HAT): "BathyElli v2.1 HAT / ell" ; - Mean Sea Levels (MSL): "BathyElli v2.1 MSL / ell"; - Lowest Astronomical Tide (LAT): "BathyElli v2.1 LAT / ell"; - Chart Datum (CD) vertical sea level reference for each tidal zone: "BathyElli v2.1 HZ / ell".

The product is a digital solution showing superficial sediments on the sea floor along coasts in mainland France.

Sea bed sediment maps for the 4 marine sub-regions prepared as part of the initial evaluation of the MSFD (Marine Strategy Framework Directive).