iStreams displays the valid hourly Portland tidal stream atlas for the current real time, in reference to the time of high water at Devonport... a smart app, fully functional offline. With tools to measure tide set and interpolated rate. The nearest Devonport HW time to the actual time is selected from the database and the relevant streams chart is displayed, together with the time period for which the chart is valid. As the time moves to the next valid period, the relevant hourly chart is au