The Severn Bore is a world-famous tidal surge. It's a peculiar natural phenomenon. Tuesday's is expected to be the only five-star bore of the year - the biggest possible one.
Certainly not boring!
A tidal bore is a strong tide that pushes up a river against a current which can sometimes cause impressive waves.
A bore can travel at a speed of between 10 and 13mph and the largest bores can reach up to two metres high.
Watch the video here: [bbc.co.uk]