How to read a tide table

Pick a point and you get that day's high and low waters with times and heights. Four a day is usual; some days have three. The values come from Tide Forecast (High/Low) by the Korea Hydrographic and Oceanographic Agency exactly as published.

Heights are in centimetres above the approximate lowest low water the agency set for that point. We do not change that datum.

• High tide is the peak of the flood. The stretch of rising water before it is deulmul (flood).
• Low tide is the bottom of the ebb. The stretch from high to low is nalmul (ebb).
• Muldori is the turn. The current stalls and reverses around each high and low water.
• Tidal range is the day's highest level minus its lowest. Large at spring tide, small at neap tide.

The mulddae name follows the lunar date, but the counting differs by coast. On the West Sea and the western South Sea the first lunar day is ilgop-mae (7-mul system); on the eastern South Sea and the East Sea the same day is yeodeol-mul (8-mul system).

So each page leads with the system used on that coast and prints the other alongside. Showing only one would give the wrong name to half the country.

We did not invent the table. We took the three names the agency's own calendar publishes each day for 726 days, confirmed that the lunar day alone fixes the value, and froze it as 30 rows. Zero days disagreed.

• Leave before low tide. Water fills the creeks behind you first. Watching the open sea tells you too late.
• Follow the signs and the loudspeaker. Closures are decided on site, not by this table.
• Do not go out in fog. Knowing the tide does not help once you lose your bearings.
• The forecast is not the water. Wind and air pressure push levels above or below the prediction.

It does not rank tides for fishing. Anglers here have said it for a long time: the mulddae number and the current strength drift apart by season, and the same mulddae runs differently over different ground. Calling a number good or bad would mean claiming knowledge we do not have.

Waves, water temperature and wind are not here. They are separate forecasts, and mixing them in blurs which number is the tide.

My harbour is not listed. Only the agency's 179 forecast points are here. We left the rest blank rather than invent them. Use the nearest point.

The table is empty. The forecast did not come back. We do not show an empty table as a forecast. Open the page again shortly.

The province says it is not listed. For 21 points the agency's list has no address. We did not guess a province from coordinates.

What is recorded. Which point you opened is never sent to the server. The privacy page has the detail.