Sea currents

But fish are the least of your worries on the beach. The force of the sea is much more dangerous than anything swimming about inside it.

Coastguards are warning the public not to swim if there is a red flag flying on a beach and to find out about local tides and currents.

Dangerous swimming

The Coastguard Agency says people should not swim if they feel unwell, for at least an hour after a meal, if they have been drinking alcohol or if they are cold and tired. They also warn against swimming alone, swimming too far out to sea if you have breathing problems.

Pollution

A recent study of UK beaches showed more than 10% are failing to meet standards for clean water. The Marine Conservation Society said polluted water was still being pumped into the sea in some areas and was winding its way onto beaches. But the water companies say the society’s standards are too tough and that 90% of British beaches pass European standards.