Last Sunday morning we got up early to see the River Severn Bore. For those that have never heard of it the Bore is a tidal phenomenon. A rising tide is concentrated by the shape of the river such that a wave forms which travels up the length of the river. The news suggested it would be a 5 star bore, the highest and supposedly most impressive of them all. There has been so much rain here in this part of the UK since December that river levels are extremely high. The Environment Agency had advised people to stay away due to the conditions. We decided to go to Newnham, a village alongside the river where we could get a good but safe view. I’d looked into the tide times and so at 08:15 we set off to ensure we got there well in advance of the 09:30 time. Arriving in the 08:50 it was a bit disconcerting to find people walking back to their cars. At the river we found it flowing very fast upstream, it was at that point that it dawned on me that I had looked up the times for when it arrived at the Severn Bore Inn much further upstream, and therefore we had missed it. So we jumped in the car to chase the Bore. As we headed north we passed a helicopter hovering off to our right, so we knew we still had chance to see it. Arriving at the Severn Bore Inn both sides of the road were rammed with car after car parked on the verges. We ended up walking for what seemed like half a mile just to get to the side of the pub. The banks were heaving with sight-seers and the river had canoeists and surfers waiting by the side, waiting to see what had been billed as the highest tidal bore of the year.
We could track the progress of the bore from the helicopter, finally we started seeing the crashing of the water at the very edge of the channel. All of a sudden about 20 canoeists and surfers appeared from the riverbank and moved into the centre of the river. I’ve seen the Severn Bore on the TV before so was expecting to see a wave of broken water right across the channel. Instead what we got was just a hump of water. Those on the water did their best and paddled like mad, but they didn’t stand a chance of riding it. They merely got lifted up by about a metre and then lowered back down as the wave passed. A few lucky ones on the very inside of the bend managed to ride the bore for a few seconds before falling off the back of it, as it straightened out.
So that was it, our first viewing of the Severn Bore was a bit of a damp squib. At least we hadn’t spent ages fighting our way into wetsuits, or dragging a canoe ½ a mile just to bob up and down for a few seconds. Still its nice to get up early on a Sunday.
Last year I was learning about wave motion as part of my OU studies. Because of this I could see what had happened and why the wave didn’t break. The river level is currently very high. Waves are formed by the circular motion of water and will only break when the bottom of the wave touches the ground, turning the motion elliptical. This is why waves in the open ocean don’t break (except in extreme weather), but as they approach the shore and the water shallows they eventually break. This never happened in our case. Even though it was the highest tide of the year the bottom of the wave was too high up due to the amount of rain we have had recently. I guess we need to go back in the summer when the river level will be much lower, so hopefully a more exciting boreing experience.