The Port of Saint John is a port complex that occupies 120 hectares (300 acres) of land along 3,900 m (12,800 ft) of waterfront of the Saint John Harbour at the mouth of the Saint John River in the city of Saint John, New Brunswick, Canada. The Port of Saint John, with facilities on both sides of the river, is noted for its extreme tidal range and river currents. Because of the semi-diurnal tides and the river influence, slack water occurs at approximately half tide and not at high or low water as at most other ports.