It happens once every 18 years
A rare “supertide” in Europe this weekend led to surges of water so high a French town briefly turned into an island. It also caused a “tidal bore” on Britain’s River Severn which created six-foot waves ripe for surfing.
Many Brits took advantage of this unique opportunity to surf down the River Severn, which is the longest in the United Kingdom. Those not equipped to go surfing simply gathered on the banks to observe the rare occurrence.