Tides

The gravitational pull of the moon, and the sun to a lesser extent, is the main driving force of the tides. Their relative positions cause tidal range (the vertical difference between high and low tide) to vary from day to day and throughout the year. It is important to check tidal height and times when planning a visit to the shore.

Unique Tidal Pattern

The marine reserve lies mid-way along the English Channel coast and because of this it has a very small tidal range. As a result, the weather can have a significant effect - onshore winds and low pressure can push waves up the shore and prevent it going out to its predicted level.

In addition the shape of the coastline and the large amount of shallow water in the area work to disrupt the tidal flow and lead to an unusual tidal pattern with a double low water. This means that at Kimmeridge there is an extended low water period of over four hours - ideal for rockpooling.

Some Important Points:

• Tides occur twice a day
• Tide times are different each day
• Tide times and ranges are predictable, which makes life a lot easier

Planning a Visit

Spring Tides: Necessary for rockpooling, are bigger tides - high tide is higher, low tide is lower. These occur at and just after a full and new moon. On the day of the full or new moon, low tide at Kimmeridge will be around midday, and will be 30-50min later for each of the next few days.

If you time your visit to coincide with the full or new moon, the tide will generally be out for most of the afternoon. Most diaries and calendars show phases of the moon.

Neap Tides: These occur around half moon - in between full and new moons.  The tidal range is much reduced and the offshore currents are weaker. These are no good for rockpooling.

Tide Tables: Kimmeridge tide tables are available from the Marine Centre and other local outlets. Alternatively, use Portland tide tables and insert the second low tide around 3 ½ hours after the normal one shown.

Check the Tides!