Essential Tide Times to Check Before Any Coastal Walk

Why a tide table is the first thing in your pack

The sea does not negotiate. On any given day around the UK coast it rises and falls twice, and on a big spring tide it can come in faster than you walk. That is the whole reason a coastal walk starts with a tide table rather than a route card. A flat that looks generous at eleven in the morning can be a waist-deep channel by one, and the water needs only ankle depth to knock you off your feet.

Being caught out rarely means drowning straight away. It usually means being stranded on a rock ledge, a sandbank or the wrong side of a tidal river with the water rising between you and the path. That is a call to the coastguard, a lifeboat launch, and a great deal of embarrassment. Fifteen minutes with a local table removes the risk almost entirely.

How to read a local tide table properly

Every table is calculated for a reference port, with adjustments for nearby places. Most are now published online by harbour authorities, but printed copies still appear on noticeboards at slipways, in village shops and at coastwatch stations, and they are worth photographing. When you read one, check four things:

• Times shift by roughly 50 minutes each day. The low tide you walked out on last Saturday is nearly six hours different this Saturday. Never reuse an old time.
• Confirm whether the times are GMT or BST. A table printed in winter and read in July is an hour out, which is easily enough to put you in the wrong place at the wrong moment.
• Look at the heights, not just the times. A low water of 0.4 metres and one of 2.1 metres give completely different beaches. Spring tides expose the most sand and come back fastest; neaps are gentler but can leave a shallow channel you had banked on crossing still full.
• Find the nearest secondary port. If you are ten miles up the coast from the reference point, the tide may arrive twenty minutes later or an hour earlier.

The Rule of Twelfths is a useful rough guide: in the six hours after low water, roughly 1/12 of the total range comes in during the first hour, 2/12 in the second, 3/12 in the third, 3/12 in the fourth, 2/12 in the fifth and 1/12 in the last. The middle two hours are when the water moves fastest. Most coastal walks are comfortable within two to three hours either side of low water — less on springs.

Work out where the water will cut you off

Read your route on the map and mark the pinch points before you go. These are the places where the sea gets behind you:

• Headlands and rocky spurs you plan to round at the base. If the tide is up, the path over the top is your escape route — know where it starts.
• Wave-cut platforms and rock ledges, lovely at low water and treacherous once the swell begins to wash over them.
• Causeways and tidal islands. Safe crossing windows are usually signposted with the times for that day. Never begin a crossing once water is on the road, and never assume the return window is the same length as the outward one.
• Estuary crossings and sandbanks. Channels shift each winter, and areas such as Morecambe Bay and the Solway demand a local guide rather than a printed line on a map.
• Caves, coves and beaches backed by cliffs or sea walls with no footpath up.

For each pinch point, decide now where you would go if the water arrived early: a set of steps, a ramp, a dune path, higher ground. An escape route you have already identified is worth ten minutes of panic later.

The day itself: weather, wind and local advice

Tide tables give the astronomical tide, not the actual one. Low pressure and a strong onshore wind can lift water levels by half a metre or more, and a storm surge can add considerably on top. Heavy rain inland raises estuary levels and pushes extra flow downstream, so a crossing that is normally dry at low water may not be. Check the inshore waters forecast as well as the tide table, look at the sea state, and read any notice at the slipway or car park. If a local says the tide runs early here, believe them.

What to carry, and what to do if the water arrives

Carry a printed tide table or a screenshot of the day's times, a fully charged phone in a waterproof pouch, a spare layer, a torch, water and a whistle. Signal is patchy in many coves, so tell someone your route and your expected return before you leave.

If you are cut off, stay on the highest ground you can reach and do not attempt to wade or swim for it — the current over a flooded channel is far stronger than it looks. Call 999 and ask for the coastguard, describe your position using landmarks or a grid reference, and stay put until help arrives. The same discipline pays off for rockpooling, foraging, sea fishing and paddling: plan around low water, watch the clock, and always leave yourself more time to get back than you think you need.