Web Map Tile Serivce is vizualisation service serving pre-calculated georeferenced tiles (images). It is a protocol standard defined by OGC (Open Geospatial Consortium). This is the service used by data.shom.fr to display maps
The WMTS offered by Shom is only available in projection Web Mercator (EPSG: 3857).
Public URL: https://services.data.shom.fr/INSPIRE/wmts