Tides

Tidal predictions, highest and lowest levels, and other related information can be found here.

Tidal predictions for UK & Irish ports

Tidal predictions for the next 28 days are available for locations in the UK & Ireland, together with the highest and lowest predicted tides from 2008 to 2026, and harmonic constants at each port – Read more →

Chart datum and ordnance datum

Tidal levels are quoted relative to chart datum (approximately the lowest level due to astronomical effects and excluding meteorological effects). Use this list to convert between chart datum and ordnance datum for selected UK and Irish ports. – Read more →

Other tidal predictions

Predictions spanning one year for the South Atlantic and Antarctica, British Overseas Territories, and the Gibraltar sea level station are available for download – Read more →

About tides

Topics relating to the tidal and sea level research carried out at the National Oceanography Centre in Liverpool – Read more →