Sources: NOAA CO-OPS (water level, predictions, wind, temperatures) and the National Weather Service (alerts, Coastal Waters Forecast). Current velocity is estimated from the rate of water-level change, not measured. Alerts refresh every 2 min, tides every 6 min, waves every 15 min. Informational only; not for navigation or life-safety decisions. Check official NWS/NOAA sources and VHF marine forecasts.