Tidal Observation Buoys and Beacons

Predicted tide data should be checked against what the water is actually doing whenever practical. Some harbours, estuaries, and offshore sites provide tidal observation buoys, current meters, tide gauges, or beacons that report or indicate live height, stream, or sea-state information. These observations are especially useful near bars, harbour entrances, tidal races, and dredged channels.

Live observations can reveal the effect of wind, pressure, river flow, and surge that is not fully represented in a printed tide table. They can also confirm whether a fair stream has started, whether a bar has enough water, or whether a race is already overfalls-prone.

Treat observations as an additional source, not a substitute for planning. Check what the buoy or beacon is measuring, the datum used, the update time, and whether the data applies at your exact position. If predictions and observations disagree, build in margin and reassess before committing to a narrow or shallow approach.