In this example, the height of the evening tide varies between 1.1m and 3.4m above chart datum, a range of 2.3m.
在此示例中,基于海图基准⾯,傍晚潮⾼在1.1~3.4⽶之间,潮差为2.3⽶。
Though the tide does not necessarily turn at high or low water, the approximate height of tide can be worked out using either the Rule of Twelfths or the Rule of Percentages.