How to plan a safe coastal walk with tide times

Why the tide decides more than you think

Britain has some of the most dramatic tides in the world. In the Bristol Channel and parts of the north-west the difference between high and low water can exceed ten metres, and even on gentler stretches of the south and east coasts the sea can travel a long way across flat sand in a couple of hours. That matters because water moves far faster than you walk. A channel you stepped over at ten in the morning can be knee-deep by noon and impassable an hour later, and it often comes in behind you, cutting off the route back rather than the route ahead.

Tides also refuse to keep convenient habits. High water arrives roughly fifty minutes later each day, and the actual time shifts further depending on where you are along the coast, the shape of the estuary, and whether it is a spring or neap tide. A beach that was gloriously open on Saturday can be thoroughly underwater at the same hour on Sunday. Any coastal plan that doesn't start with the tide table isn't really a plan.

How to read a tide table properly

You can find tide times for most UK stretches of coast well in advance, from harbour offices, visitor centres, printed tide tables and tide clocks, or simply noted on the noticeboard at the car park where you're starting. Whatever the source, use these habits:

• Look at high water, not low water. Low tide tells you what's exposed now; high tide tells you where the limit of your walk really is.
• Note the time and height of both high waters if there are two in the day, plus the low water between them. The range is what creates the speed.
• Check whether it's a spring or neap tide. Spring tides follow the new and full moon and bring the highest and lowest water. Neaps are gentler — but only relatively.
• Add local adjustment. Tables are usually given for a named port or headland, and times can differ by twenty or thirty minutes a few miles along the coast.

Write the key times down on paper or the back of your hand. Phone batteries die, and wet screens are useless.

Build the tide into the route, not the other way round

Start by choosing a walk you can comfortably finish inside one tidal window, with a margin. A common rule of thumb is to be off any tidal section at least two hours before high water, and to allow an extra hour on top of your normal walking time for rough ground. Shingle, soft sand, wet rocks and seaweed-covered causeways all slow you down considerably — a coastal mile can take twice as long as an inland one.

It's also worth identifying a bail-out before you set off. Is there a path up the cliff, a slipway, a set of steps to higher ground? If the answer is no, that stretch of coast is a fair-weather, low-tide-only proposition, and you should treat it with respect. Never wade a flooded causeway or ford on the coast. There's no way of knowing the depth or the strength of the current, and it takes very little moving water to knock an adult off their feet.

Pack for the coast, not for the forecast

Coastal weather turns quickly, and sea breezes can arrive on an otherwise still afternoon. Lightweight waterproofs, worn or packed, are worth their weight on any coastal walk, along with a warm layer even in summer. Beyond that:

• A charged phone in a waterproof pouch, plus a power bank if you're out all day.
• Plenty of water and a snack — coastal walking is thirstier work than it looks.
• Sturdy footwear with grip for wet rock and loose shingle.
• Sunscreen and a hat; there's little shade on an exposed headland.
• A paper map or guidebook, and a whistle for emergencies.

If you're walking with children or dogs, keep them close near the water's edge. Rips, sudden drops and slippery rocks are the usual culprits, and dogs are particularly prone to getting cut off in gullies.

Tell someone your route — and tell them when you're back

Before you leave, tell a friend or family member your starting point, your intended route, and the time you expect to be back. Add the tide times you're working to, so they know when to worry. Then actually message them when you finish. It takes ten seconds, and it means a missed check-in is a real signal rather than a guess.

If the worst happens, call 999 and ask for the coastguard. Give your location as precisely as you can — a grid reference, a what3words square, or a clear description of the nearest landmark. Don't wait to see whether the situation resolves itself; the tide rarely does.

On the day: read the ground and the water

Keep an eye on the sea as you walk, not just your feet. Watch where the water is reaching and how fast it's filling the gullies you crossed earlier. If you find yourself hurrying, that's information — turn back the way you came rather than pushing on to a point that may or may not have an exit. Seaweed lines, damp sand above the current waterline and fresh debris all show how high the tide gets, and it always gets higher than you expect.

The coast rewards patience and preparation. Get the tide times right, leave room in the day, dress for the worst and tell someone where you're going — then you can relax and enjoy one of the finest walks Britain has to offer.