Tidewell
How accurate are Tidewell’s tide times?
Quick answer
Tidewell calculates tide times using harmonic tidal analysis — the same well-established method used to produce most published tide tables. Predictions are typically accurate to within minutes for a normal day, but they are estimates and should never be used for navigation or safety-critical decisions.
How the predictions are made
Every tide time is computed on your device from tidal-constituent data — the harmonic building blocks (driven mainly by the Moon and Sun) that describe how the water level at a station rises and falls. This is the standard technique behind official tide tables worldwide.
What can shift the real tide
Weather, air pressure, wind surge and local coastal geography can all push the actual water level away from the prediction, sometimes by a meaningful margin during storms. No app or tide table can account for weather in advance — treat predictions as the expected baseline, not a guarantee.
Not for navigation
Tidewell is a planning and awareness tool for beach trips, fishing, surfing and coastal walks. It is not affiliated with any hydrographic office and must not be relied on for navigation, diving, or any situation where being wrong about the water level could be dangerous — always consult official marine charts and your local authority for those.
Independent tide-prediction app. Tide predictions are estimates and must not be used for navigation.