Several factors affect the tides in the English Channel. The Dover Strait is renowned for having strong tidal flows with a large rise and fall in water from high to low tide. There are two types of tide, the ‘EBB’ tide and the ‘FLOOD’ tide.
Ebb Tide: This tide comes from the North East down the Channel towards Folkestone. It begins 4.5 hours after high water to 2 hours before high water (Dover).
Flood Tide: Travels up the Channel from the South West towards the North Sea. It occurs 1.5 hours before high tide to 4.5 hours after high water (Dover).
An important factor in tidal control is the moon. When the sun, moon and earth are aligned the tides are at their maximum strength and are known as SPRING tides. When the moon is at 90° to the earth, we have weak tides called NEAP tides. The tides alternate in a two weekly cycle. High water during spring tides is at roughly midday and midnight (GMT) and high water during Neaps is in the region of 6am and 6pm (GMT). The mean height for a high water Spring tide is 6.8 metres and a Neap tide is 5.3 metres.
The preferred time for swims to take place is on the Neap tides as the period before the tide turns is much longer and the tidal flow, especially at the Cape, is much slower. Your pilot however, is very knowledgeable in the way the tides work and therefore advice from him is crucial. There are places where the tide will help your swim and other areas where you will be hindered.
You can probably now understand, why time is critical on your swim. If you spend a lot of time on your feeds; for example, 3 minutes for a feed every hour then on a 14-hour swim you will have lost 42 minutes. This can be crucial towards the end of your swim when the tide is about to change. You may think you are nearing the end of your swim, when in fact the tide has suddenly changed direction and is now moving against you. This can result in a further 2 hours or more to land rather than the 20 minute distance it may seem to the naked / goggled eye.
High Tide 7.9 m Spring Tide Folkestone Harbour
6 Hrs Later low tide Folkestone Harbour. Tide has dropped 7,9m or 25.91 ft this strong tide was between 5-6 knots 4 miles off Folkestone this was partly due to a NE wind.