Tide times and safety on British beaches

Why the Tide Matters More Than You Think

Most of us check the weather forecast before a coastal walk. Far fewer of us check the tide times. Yet on British beaches, the sea is often the bigger hazard. The tide can move faster than you can walk, and it does not need to be a spring tide or a storm to trap you against a cliff. On many stretches of the UK coast, the water can advance at walking pace or faster, and the beach you crossed an hour ago may be shoulder-deep by the time you turn back.

The good news is that tides are predictable to the minute, and tide tables are freely available for almost every stretch of coast. A little planning turns a potentially dangerous outing into a relaxing one.

Reading a Tide Table Before You Set Off

Tide tables give two high waters and two low waters each day for a named port. Times are usually local, but you should check whether the table uses GMT or BST, because an hour's error can matter a great deal on a beach with a shallow gradient.

Look for more than just the time of low water. The height of the tide, given in metres, tells you how much beach will be exposed. A low water of 0.4 metres leaves far more sand than a low water of 1.8 metres, even though both are called "low tide".

• Find your nearest standard port and note the highs and lows for the day, checking the time zone.
• Note the tidal range — the difference between high and low water. A big range means fast-moving water and large areas of beach that flood quickly.
• Allow a safety margin of around two hours either side of low water for any route that crosses sand or rounds a headland.
• Plan your walk to finish before the tide turns, not exactly as it turns.

If you only remember one rule, make it this: never start a below-cliff or beach route on a falling tide unless you have a reliable inland escape route.

The Classic Trap: Walking Below Cliffs

Cliff-backed beaches are some of the most beautiful walking in Britain — and some of the most deceptive. At low water you might have a wide sandy bay; within a couple of hours the same spot can be a narrow strip of shingle with a rock face behind you. There is often no way up. Sea cliffs are not scrambles you can simply climb because you are in a hurry.

Headlands are the worst offenders. A route that rounds a point at low water may be impassable long before high tide, and the alternative may be a long detour. If you are walking a coastal path above the cliffs, you are usually fine, but any section that drops to the shore needs tide planning.

Watch for these warning signs:

• Fresh seaweed, wet sand, or a line of debris high up the beach — clues that the sea reaches there regularly.
• Narrow beaches with no visible path, steps, or gully leading upwards.
• Signs or notices warning of tidal cut-off, which are there for a reason.
• Soft mud or sinking sand near estuaries, which can trap you independently of the tide.

Estuaries, Quicksand and Fast-Incoming Water

Estuary crossings are a category of their own. Some, such as the wide sandy inlets on both sides of the country, have famously fast tides and areas of soft mud. Even experienced walkers have been caught out. Unless you know the route well and have checked the tide, treat estuary crossings as no-go.

Where a river meets the sea, the incoming tide can push upstream as a wave or surge, and it can arrive quicker than you expect. If you can see water beginning to run back up a channel, get to firm ground immediately. Do not wait to see how far it comes.

Local Warnings, Signs and People Who Know

Tide tables do not know about local quirks. Some beaches have unusual currents, shifting sandbanks, or areas that flood from behind as well as in front. Local information fills that gap.

• Read the notices at car parks, beach entrances and slipways. They often give the exact cut-off times or a safe crossing window.
• Ask a local — a harbourmaster, coastguard station, café owner or lifeboat volunteer will usually be happy to advise.
• Check forecasts for wind and swell. A strong onshore wind or a big swell can push the sea further up the beach than the tide table alone suggests.
• Tell someone your plan, including your intended route and the time you expect to be back.

Always Have a Plan B

Before you commit to a below-cliff route, identify a backup. That might be a path up to the cliff top, a road inland, or simply a decision to turn around early. If the only option when the tide comes in is to run, you have not got a backup.

Carry a paper map or a charged device, and know where the nearest escape points are. If the tide looks like it will beat you, turn back early. The beach will still be there tomorrow.

The coastline of Britain rewards walkers who respect it. Check the tide, read the local warnings, keep an inland route in mind, and you will enjoy the shore in safety. That is the difference between a memorable walk and a rescue call.