Liverpool Tide Predictions tends to mean the values in Lavers annual
pocket tidetables which are widely available throughout the NorthWest. Most
tidal data is presented with time as UTC (GMT) so an hour has to be added during Summer
Time.
For example, Glasson Dock actually specifies these tables as relevant to their
opening times.
Lavers Tables are based on the POLTIPS-3 model (from National Oceanographic Centre
Liverpool with 240 terms in the model): see for next 4 weeks for
Gladstone Dock.
Also
current and next month tables for
Gladstone Dock.
Reeds Almanac and many chart plotters use the Easy-tide model (a simplified model suitable for leisure use) which is available from Easy Tide ( free here for the next 7 days) for Gladstone Dock.
Note that Liverpool Marina booklet contains tidal predictions based on Easy-Tide ( free here for the next 7 days) for Alfred Dock. These are about 5 minutes later than those for Gladstone Dock but are more appropriate for the marina location.
Remember that these are all PREDICTIONS. Actual tidegauge data are
available from
ntslf(National Tide and Sea Level Facility). This shows that weather
(pressure and wind effects) can change tide heights by as much as 1 metre.
See also
tide-gauge data download.
The Hydrographic Office (Admiralty) also produce a more precise model (TotalTide) which is aimed at commercial users. See here.
CAMS (Centre for Applied Marine Sciences, Bangor University) have developed tidal models and give tables for tides at Liverpool here (click on tide tables then on Liverpool).