Tidal heights and the rule of twelfths
For those skippers who need to make a quick calculation or don’t have access to specific tidal curves for their location, it is possible to make an approximation using a system called the Rule of Twelfths. This is a simple method used to estimate the height of tide at any given time during the tidal cycle. It is based on the idea that the rise and fall of the tide is not constant, but follows a predictable pattern than can be divided into twelve parts.
Understanding tide tables and tidal curves
There are many factors that influence local tidal patterns and it’s essential for every sailor to have a good understanding of tide tables and tidal charts to ensure they can calculate the level of tide at any given time.
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