Tidal Ranges increase and decrease twice every 28 days, as the moon waxes and wanes.

• Full Moon - Spring Tides
• First Quarter - Neap Tides
• New Moon - Spring Tides
• Third Quarter - Neap Tides

The following tidal curves have been produced using tidal data for Cardiff, but 2010 & 2011 Spring and Neap tide dates will be consistent throughout the UK.

These graphs are provided as an aid to dive planning. It is the responsibility of the dive manager to obtain correct tide and weather information for any site you wish to dive.

When planning dives in strong tidal areas, it is best to select dates with a small tidal range, more commonly called a Neap Tide. The reduced tidal flow around neap tides usually results in improved water visibility and increased "Slack Water" times.

For the purpose of regularity across these charts, certain dates in each month are repeated. Weekend dates are highlighted in yellow.

Graphs for 2012 spring and neap tides will be added early 2011.

For further information about these graphs, or to find out how they can be used for any port or location in Western Europe, please check out our additional information page.