2.5 Tidal streams

In order for the tide to rise and fall at a given location, water must move from one place to another. These horizontal movements of water are known as tidal streams.

In many areas frequented by sea kayakers, steep rocky coastlines make the height of tide less of a concern. However, tidal streams often run at 2-3 kt and sometimes much faster. Given that tidal streams can move as fast as we can paddle, they clearly need to be accounted for in our plans.

Tidal stream running at 4+ knots at the south tip of Skomer, Pembrokeshire. The stream is running from right to left, making this channel look like a whitewater river. After a few attempts, our group just made it upstream through the constricted part of the channel, narrowly avoiding having to retrace our route back around the island.

This map below shows the directions of the main flood tidal streams (i.e. those that occur in the run up to high water at Dover and Liverpool) around the UK.

Main flood tidal streams around the UK. Notice how tide floods in from both north and south to fill the Irish Sea. Also note how the flood stream runs down the east coast and eastwards along the south coast to meet at the Thames Estuary.