Waves of up to 17 metres high do exist in the North Sea, despite the Dutch water board’s assertions that they are a myth, says the national lifeboat society KNRM.

During last November’s severe storm, waves of almost 20 metres were recorded in the sea close to the island of Schiermonnikoog.
The water board claimed the measurements are wrong and the waves could not have been higher than 8.4 metres.
But KNRM spokesman Kees Brinkman told ANP that the shallow waters around the Netherlands create massive breakers known as ‘white tigers’ and are very dangerous to shipping.