Entry 1 High, low, and the hours in between
A tide table lists the times and heights of high and low water, but the water does not move at a constant rate between them — it moves fastest around the midpoint and slowest near each peak, a pattern worth knowing before timing a passage through a shallow or narrow spot.
Entry 2 Why the datum line matters
Every tide height on a table is measured from a reference point, usually a long-term average low water mark, not from the seafloor itself. A charted depth plus the tide height for that moment gives the real depth under the keel, not either number alone.
Entry 3 Planning around a tide, not just checking it
Knowing the tide at departure time is only half the job — knowing it at your expected return time matters just as much, especially for a route through a shallow inlet or over a sandbar that might be passable at noon and nearly dry by four.
Entry 4 Questions people ask
Do tide times stay the same every day?
No — tide times shift by roughly 25 to 50 minutes later each day in most locations, following the lunar cycle rather than the clock.
Is a tide table enough, or do I need current information too?
For many routes you need both — tide height and current direction/speed can be reported separately and don't always peak at the same moment.