Saint-Malo is the second largest commercial port in Brittany, despite the fact that access is made difficult by the high tides and the rocky sea floor. Four lighthouses mark the different access channels. The port is made up of two very distinct areas. The fore-port, subject to the tide, welcomes ferry traffic with England and the Channel Islands, large liners and the skiffs of the Bas-Sablons marina. The four inner basins – Vauban, Duguay-Trouin, Jacques-Cartier and Bouvet – are accessible via the Naye lock to ships up to 150 metres long and 21 metres wide with a draught of 9 metres.