Why the tide decides your day

On the coast, the tide is not background scenery — it is the clock that sets everything else running. Around the UK we have two high waters and two low waters in roughly every 24 hours and 50 minutes, which is why the tide slips later each day and why a spot that was perfect on Saturday morning may be under water by Sunday afternoon. The range between high and low water varies hugely too. Spring tides, which arrive near the full and new moon, push furthest up the beach and drain the mudflats furthest out. Neap tides, around the first and third quarter, are gentler and leave waders closer to the shore.

Knowing which you are walking into changes what you see and, more importantly, whether you get back to the car dry.

Reading a tide table like a local

A tide table gives you high and low water times and heights for a named port or standard port, plus corrections for nearby places. Learn three habits. First, check the height, not just the time: a 4.6 metre high water and a 3.2 metre one behave very differently on a flat estuary. Second, look at the height of low water if you plan to cross sand or mud — a neap low may leave channels you expected to be dry still full of water. Third, remember the rule of twelfths: in the six hours between low and high water, roughly one twelfth of the total rise arrives in the first hour, two in the second, three in the third, three in the fourth, two in the fifth and one in the sixth. The middle hours move fastest, and that is when people get caught out.

Waders, mudflats and the falling tide

Most estuary birding is a game of chase. As the water drops, hundreds of dunlin, knot, bar-tailed godwit and grey plover follow the ebbing edge out across the exposed mud, feeding hard on the freshly uncovered invertebrate layer. Oystercatchers and curlew work the cockle beds and the softer channels, while shelduck and brent geese graze the eelgrass and saltmarsh edges.

Then everything reverses. Two to three hours before high water the birds begin to drift back, and the last hour of the flood concentrates them onto shrinking islands of mud before they lift, in loose, shimmering flocks, to a high tide roost. Those roosts — a shingle ridge, a saltmarsh hump, a quiet field behind the sea wall — are the real prize. Arrive at a roost about two hours before high water, settle well back, and let the birds come to you. Use a scope from distance rather than walking onto the roost, which costs the flock precious energy.

Cliffs, headlands and the rising tide

Cliff birding works on a different logic. Seabird cities — guillemot, razorbill, kittiwake, fulmar — are best watched in calm, settled conditions, and many are most active in the first few hours after high water. But the same tide that brings the birds close to the cliff base can also seal your route home. Wave-cut platforms and rocky inlets that are walkable at low water become impassable surprisingly fast, and in places such as Morecambe Bay or the Solway the incoming tide moves at the speed of a brisk walk, sometimes faster, cutting off the channels behind you first.

Headlands looking out over tide races and offshore reefs reward you with gannets, Manx shearwaters, and in winter divers and grebes. Always give yourself a route that climbs rather than one that relies on a beach remaining open.

Essential safety checks before you set off

• Tide times and heights for the nearest standard port, plus local corrections. Note both the high and the low.
• Timings for any crossing: know how long the walk in takes, and aim to be back at least two hours before high water — not exactly on it.
• Escape routes: identify high ground, steps cut into the cliff, or a path that stays above the tideline.
• Weather and swell: an onshore wind and a big swell can push water further up than the table suggests.
• Ground conditions: soft mud, quicksand and shifting sandbanks are common on estuaries — never test unknown ground alone.
• Tell someone your route and expected return, and carry a charged phone, though expect signal blackspots.
• Kit: grippy boots, waterproofs, water, and a warm layer for the long sit at a roost.

Timing your visit for better birding

Once you start planning around the water, the birds stop being a lottery. Two hours either side of high water suits roost watching and estuary counts; the first two hours of the ebb suit feeding flocks on freshly exposed mud; the last hour of the flood is often the most dramatic, as birds concertina towards the shore. Keep a small notebook of times, heights and what you saw, and within a season you will have your own local tide almanac — far more useful than anyone else's.

Respect the water, give the birds distance, and the coast will keep rewarding you.