Tides affect the water level not only on the coast, exposing reefs and rocks, but also on the entire surface of the ocean, so it is dangerous and must-know thing for sailors, kayakers, and surfers, including kitesurfing, windsurfing and foiling as its branches.
To stay safe and just learn more about this weather phenomenon, read the collection of articles about tides forecasting from the experts of the leading pro weather forecast app for wind sports and outdoors recognized by WMO.
Imagine entering a bay on a yacht planning an anchorage. The depth is good. Almost no waves. A great place for “parking”. But the next morning you see less water and the boat falling on board. This means that you entered the bay at high flow. And in the morning the water left the banks.
Water height fluctuates constantly. And if that's what happens, it has to be counted from something, right? It's got to be zero depth. In other words, the datum, what's taken for zero depth. These are two of the most common datums in the world: LAT (Lowest Astronomical Tide) or the lowest theoretical water level and MLLW (Mean Lower Low Water) or the average value of the lower low water.
If you are a yachtsman, and especially one who travels long distances, it is important to know the places with the highest tides in the world. The reasons for this are clear. To help you navigate the sea, we took a list of 50 such locations compiled by the U.S. National Oceanic and Atmospheric Administration (NOAA). It's not very hard to read, but it takes some time to understand the patterns, which can be critically lacking during a challenging yacht crossing.
In addition to the two main concepts related to tides — high tide and low tide, respectively — there are more than a dozen others. The tidal range is the third most important thing, which comes from the first two, as you might guess. It is the height difference between a high tide (rise in water level) and a low tide (fall) at any given location.
To predict tides we use tides tables — the main tool for getting information about tides. They are also sometimes called tide schedules, predictions, reports, forecasts, etc. Tide tables show high and low tides, indicating the time and height of these water level for a particular coastal area. These tables make it possible to pre-calculate the time and heights of high and low waters, as well as the heights of levels at intermediate moments with sufficient accuracy for practical purposes.
Text: Ivan Kuznetsov and others of the Windy.app team
Cover photo: Waipio Valley Beach, Big Island, Hawaii, United States. Michael Olsen / Unsplash