What is the littoral zone?

The littoral zone is that part of the river or sea which is closest to the shore. It extends from the shoreline to 600 feet (183 metres) out into the water and is divided into three zones called supralittoral, intertidal and sublittoral. The zone is a tricky area when it comes to predicting water conditions because so many factors affect it. Coastal currents, onshore and offshore winds, reefs, bays and the share of the shoreline are some of the things sailors have to deal with when passing through this zone.