Tidal Atlas

A tidal atlas is a navigational reference that shows the predicted direction and rate of tidal streams across a defined coastal area, harbour approach, strait, or channel. Each chart is usually tied to an hour before or after high water at a reference port, using arrows and figures to show where and how strongly the tide will flow.

For boaters, a tidal atlas helps time departures, clear tidal gates, choose safer inshore routes, and avoid losing speed or steerage in adverse flow. It is especially important where a Tidal Stream accelerates around headlands, over bars, or through narrows, and should be considered with Tidal Current predictions, Chart Datum, depth, wind, and sea state.

Digital tidal atlases and stream maps make this information easier to visualise over time. In PredictWind, tidal current layers can be viewed alongside wind and wave forecasts, then considered during Weather Routing and Departure Planning to optimise speed, comfort, and fuel use.