The National Coastwatch Institution station at Gwennap Head near Lands End, is a voluntary maritime coastwatch charity who’s mission is to keep a visual lookout for boats and coast users in danger “Eyes along the coast”. The Gwennap Head NCI station looks out over the notoriously dangerous tidal reef known as The Runnelstone, which extends out around a mile from the coast. In order for visitors as well as new volunteers to be able to visualise the submerged reef, we created an infographic image using bathymetric and land GIS data available from the British national archives.