Start with the route restriction
A tide table becomes useful only after you know what the route requires. Mark each headland, cove, or shoreline pinch point where a map says travel depends on tide height or timing. Check whether the map identifies a beach passage, an overland trail, or a section that should not be rounded at all. Olympic National Park’s coastal guidance distinguishes headlands that may be passable below a stated height from places that require an overland route. It also warns that one low tide may open one headland but not the next. The restriction belongs to the specific place and map; there is no general “low enough” number for every coast. Route source
This first pass turns a long shoreline into a sequence of questions. Where is the last safe point before the restriction? What is the mapped alternative if the beach route is unavailable? Is that alternative open and suitable for the group? A tide chart cannot answer those route questions by itself. The land manager’s current route page, map legend, and access notices supply the geographic meaning that a prediction line lacks. Olympic National Park asks coastal hikers to use a topographic map together with tide information for precisely this reason. Route source
Choose a station and read its clock
Select a prediction station that represents the coast you intend to travel, and check its location rather than choosing the nearest name on a screen without context. NOAA’s prediction service lets users search by station name, identifier, or coordinates; its help page explains that predictions are available only for analyzed locations. Some stations are subordinate stations whose high and low values are adjusted from a reference station. Treat the station identity as part of the data, not a detail to skip. Data guide
Read the date, local time setting, height units, and datum shown with the prediction. NOAA’s tool lets users choose time references such as local time with daylight adjustment, local standard time, or GMT, and lets users select feet or metres. A time copied into a trip plan without its zone can be wrong by an hour or more; a height without units is not a usable comparison. When matching a chart’s values to a route map, make sure the map and prediction refer to compatible height conventions, and follow the chart or manager’s instructions if they specify a source or datum. Data guide
Build a window, not a single appointment
Compare each mapped restriction with the relevant predicted high and low points for that day. The route map may state a maximum height, a direction to pass near low water, or a different land route. Use that local instruction as the planning rule. Olympic National Park says some coastal locations are passable only at lower tides and advises checking predictions before choosing a day. Its wilderness-coast page describes one to two hours before low tide as the safest time for rounding headlands in that setting, while also warning that timing and thresholds differ by place. Use such guidance only for the route it describes; do not turn it into a universal schedule. Route source Route source
For a planning exercise, imagine a fictional map that says a particular headland is passable below 2 feet, and a matching chart that predicts a 0.8-foot low at 10 a.m. That does not mean the group should arrive at 10, or that the headland is safe at that height under every condition. It means the planned crossing needs to fit inside a route-specific window, with time to reach it before the low, pass the restriction, and continue to an exit or turnaround point. Add realistic walking time over the actual terrain, breaks, navigation pauses, and margin for slower travel. If the window works only when every estimate is exact, choose another route or day. This example is invented to demonstrate the arithmetic, not a route report.
Let the forecast and the terrain overrule the table
Predictions describe expected tidal water levels; they do not capture every wave, run-up, or weather effect at a beach. Olympic National Park warns that strong winds and storms can significantly elevate tides and make normally passable places hazardous or impassable. It directs visitors to check the marine forecast and remain attentive to conditions. A generous-looking predicted window is not a reason to ignore surf, wind, heavy rain, a closure, or a ranger’s direction. If actual water is already reaching the route, retreat to mapped high ground or the designated overland alternative rather than trying to beat it. Route source Route source
Before leaving, write down the restriction, the station and date used, the relevant high and low predictions, the map-defined route alternative, and a turnaround time that leaves room to return. Carry the chart and map in a form that remains available without a phone signal, and keep track of time as the park advises. Then check live alerts and forecasts again close to departure. If a closure, weather change, timing slip, or uncertain map note removes the margin, switch to a route that does not depend on the missed window. Tide planning is a way to ask better questions of the coast; it is not a guarantee that the coast will match the table. Route source
Sources & further reading
Sources, dates, or details to query? Read our editorial approach.
