Using Tide Tables
Tide tables list the predicted times and heights of high water (HW) and low water (LW) for standard ports, for every day of the year. They are published in the nautical almanac (or the dedicated Admiralty Tide Tables).
To find the height of tide at a given time, you need: the times and heights of the HW and LW bracketing your required time, and the shape of the tidal curve for that port. You then use the tidal curve method to interpolate.
Key Points
- Tide tables give HW and LW times and heights for standard ports
- Times are usually in UT (Universal Time) — add 1 hour for BST
- Heights are measured above Chart Datum
- Use tidal curves to find height at intermediate times
Tip: Always check whether the tide tables are in UT or local time. UK tide tables are usually UT — add 1 hour during British Summer Time (last Sunday in March to last Sunday in October).