A tidal window is a time window in which a ship is allowed to enter the channel.
A tidal window is a time window in which a ship is allowed to enter the channel. During the channel transit, tidal windows indicate the different opening and closing times at different locations. Between those points in time it is safe to sail through a particular part of the channel. The length of the tidal window depends especially on the astronomical tide, ship characteristics (like draft), wave climate and meteorological conditions. The more unfavorable the situation gets (for example more wind or waves), the narrower the tidal window becomes. In the most extreme situation no tidal window is available and the vessel has to wait for a next tide and better circumstances.