Tidal curve 1

The Tidal Curve is another method of determining times of high and low water.
Before you use the curve, note the times and heights of tide for the day from the tide table. Let’s again use Portsmouth on September 1st.
First you have to enter the time of the day nearest high water – if it is now 09:45 then we take the next high water at 9:56.
Now we mark the low water on the lower scale and the high water on the upper scale, and connect both values with a straight line.