The Mercator was a training ship, launched by the Belgian Royal Marine in 1932. It was used for the training of officers of the Merchant Navy until 1960. It was the depot ship for coastal forces based in Freetown, Sierra Leone. The coastal forces boats patrolled the West African Coast to protect the convoys coming from South Africa to the UK. The Mercator was their "mother ship".

The Mercator was transformed into a museum in 1961, and is now moored at Ostend.