Morecambe Bay is a large sandy bay in the north west of England and is a designated European wildlife and Ramsar site. The Bay stretches from Walney Island in the north to Fleetwood in the south, taking in the coastal resorts of Grange over Sands, Arnside and Morecambe. With regard to the AONB, approximately 40% of the designated AONB area is within the Bay and therefore covered by tidal waters twice a day!

The Arnside Bore © Adam Donaldson

The tidal bore results from a combination of the high tidal range and the shape of the bay as it narrows into the Kent Estuary at Arnside. The water enters the tapering estuary and the rising waters become confined which results in a distinct wave developing, which can be anything from a few centimetres to almost a metre high on full spring tides. 

Predicted tides of 9.5m or more are needed before it is likely that a full bore will rise and even then the bore is inconsistent and sometimes doesn't really develop at all.

They seem to be affected by the wind strength and direction, the shifting channels and sand bars and even the volume of water coming down the River Kent. 

The coastal habitats can be windswept and invigorating and (when the weather is clear) provide spectacular open views across the estuary and Morecambe Bay and into the mountains and hills of the Lake District.

These areas are characterised by areas of salt marsh and broad expanses of mud and sand flats. These form part of a shallow inlet and bay estuarine system of international importance for the conservation of wild birds and valued habitats designated both as SPA and SAC.

The mudflats provide rich feeding grounds that support large populations of wintering wading birds, including oystercatcher, dunlin, knot and wintering wildfowl including shelduck, pintail and eider, which add much to the natural beauty of the landscape.

Venturing onto the sands is hazardous due to the speed of the incoming tide, the presence of quick sands and deep channels. The intertidal sand and mudflats are a dynamic environment and can change in form and character with every tide. The official Queen's guide to the sands leads a considerable number of Cross Bay walks each year from Arnside to Kents Bank.

Coastguard rescue jet ski

To check for the times and heights of tides visit the tide table pages at the BBC website (for Barrow Ramsden Dock) or the Admiralty Easy Tide Website linked to Arnside.

Silverdale School 701 club produced a Morecambe Bay Advice leaflet which you can download here or by clicking on the cover image on the right. The project was funded by Lancashire County Council and the AONB Sustainable Development Fund.

There is a seasonal siren signal at Arnside, provided by South Lakeland District Council, to warn of the incoming tide. The siren is sounded twice before each daylight high tide, the first time at roughly 20 minutes before the tidal bore is due. 

The second siren warning is sounded as the bore reaches Blackstone Point at New Barns Bay, around 5 minutes before the bore reaches Arnside pier. It has to be said that giving timings for the bore is not an exact science in the way that tidetables are.

The estuary has an HM Coastguard rescue team based at Arnside, who operate a rescue craft in the Bay, with additional rescue services provide by the RLNI at Morecambe and the Bay Search and Rescue group at Flookburgh.