About every month, Arnside battens down the hatches and prepares itself for a tidal wave – the Arnside Bore. The Bore is a tidal phenomenon which occurs in relatively few locations worldwide and is caused by the leading edge of the incoming tide being forced through a narrowing bay causing a wave against the direction of the bay’s current. Hence, the Arnside Bore is a true tidal wave – although this shouldn’t be confused with a tsunami!
The Arnside bore is caused by a combination of the high tidal range and the shape of the bay which narrows into the Kent Esturary at Arnside. The size of the bore wave can be quite hard to predict, ranging from a few centimetres to almost a metre high! To give yourself the best chance of seeing an impressive bore wave, make sure you visit during a predicted tide of 9.5m or more, or preferably a spring tide. If you can combine this with recent rain in the lakes and a strong westerly wind, then you are sure to be onto a winner!
Arnside is probably the best place to watch the bore because, not only is there a small pier, but South Lakeland District Council also provide a seasonal siren, to warn of the incoming tide. The siren is sounded twice before each daylight high tide, the first time roughly 15 to 20 minutes before the tidal bore is due (it is not an exact science). The second siren is sounded as the bore reaches Blackstone Point (New Barns), which is just further down the bay.
Even if your visit isn’t timed well for a bore wave, Arnside is still worth a visit for a bit of bird spotting. The mud flats and shallow water provide rich feeding for birds such as Oystercatchers, Dunlin, Knots, Herons, Shelducks and many more. The National Trust car park at Arnside Knott is a short walk back to the village and the pier, but parking in the village can be quite hard on sunny days, and it’s a nice walk anyway.