Tide and Current Guides

Short, plain-language explainers on the science behind tide and current predictions.

Tidal Coefficients Explained

The 20 to 120 scale that summarizes how large a tide will be, and how the Moon drives it.

Flood, Ebb, and Slack: How Tidal Currents Work

Flood, ebb, and slack water, and why the strongest current is not always at high tide.

Tidal Datums and Tide Heights

Chart datum, LAT, MLLW, and what the number in a tide height actually means.

How Tide Predictions Are Calculated

Harmonic analysis, the constituents behind the tide, and why weather makes reality differ.