The tide comes first

Every coastal walk begins with a tide table, not a map. Around the UK's more indented stretches — the estuaries of the west country, the sand flats of the north-west, the drowned valleys of Wales and western Scotland — the line between path and sea shifts by hundreds of metres twice a day. A route that feels generous and open at low water can be a narrow, wet ledge at high water, or gone entirely.

The practical rule is to plan around low water. Check predictions for the nearest reference port rather than the nearest town, because the difference between two points a few miles apart can be half an hour or more. Note whether you are on springs or neaps: spring tides push further up beaches and through narrow gaps, often by a metre or more, and they run harder too. A crossing that works comfortably on a neap may be genuinely impassable on a spring, even in calm weather.

Wind and pressure matter as much as the printed figures. A strong onshore breeze and a low-pressure system can bring high water in earlier and higher than predicted. If you are walking in unsettled weather, take the pessimistic reading of the table.

Choosing your window

Aim to be through any tidal section within two to three hours either side of low water, and build in an extra hour of slack. On firm path you can reckon on roughly four kilometres an hour; on sand, shingle and wet rock, closer to three, and slower again with a pack or a headwind.

Work out the length of the tidal stretch first, then the time it will take, then subtract it from your window. If the numbers are tight, change the plan rather than the pace. Three useful habits:

• Write the low-water time on the back of your hand or in your phone notes, and set an alarm for your turn-around.
• Carry a 1:25,000 map so you can measure the tidal section properly, not guess it from a screen.
• Check sunset as well as the tide — a late low water in winter leaves no margin for an unexpected delay.

What counts as a tidal access point

Tidal access points are the places where the coast lets you in and out, and they are rarely obvious from a distance. On a map, look for the thin lines and the telltale gaps: a path that stops at the sand and resumes on the far side, a break in a sea wall, a causeway linking an island to the mainland. On the ground, the useful ones tend to be:

• Causeways and necks — often with a short, sharp inundation window rather than a long shallow one.
• Sand and shingle spits — passable on foot at low water, but with soft patches and channels that fill first and empty last.
• Stepping stones and fords — delightful when dry, treacherous when wet, and usually slippery with algae on the shaded side.
• Slipways, ramps and harbour walls — reliable, but check whether the top of the ramp is private or gated.
• Gaps between headlands — a pleasant beach at half tide, a wall of water against rock at full.

Escape routes and the point of no return

Before you commit to a tidal stretch, look up and look inland. Identify at least one way off the beach that does not depend on the tide — a flight of steps, a lane, a side valley, a break in the cliff line. Then decide where your point of no return sits: the place beyond which retreat costs more time than continuing.

If you are caught out, do not swim for it. Cold water, currents and a heavy pack make that a last resort. Move to high ground above the reach of the waves, stay put, and wait for the tide to turn. Carry a torch, a charged phone in a dry bag, and a spare layer. Tell someone your route and your expected finish time, and message them when you are clear of the tidal section.

Cliffs, ground and loose edges

Soft cliffs of clay, sand and glacial till crumble constantly, and the top edge is often undercut and hollow. Keep well back from the lip — a good few metres on unstable ground, more after rain — and never trust a grassy overhang. Descents to beaches are frequently the loosest part of the walk: scree, root steps and eroded gullies. Take them slowly, use your hands where it helps, and avoid descending anything you would not happily climb back up.

Heathland above the cliffs has its own hazards. Sandy paths erode into steep-sided gullies, gorse hides holes and roots, and the ground can be boggy in the dips even in summer. Gaiters and boots with real grip earn their place here.

Wildlife, heathland and leaving it as you found it

Coastal heath is one of the UK's rarer habitats, and the strip between cliff and farmland supports ground-nesting birds such as skylark, meadow pipit, curlew and oystercatcher. Between March and July, keep dogs close and on a lead near nesting areas, and stay on the path rather than cutting across the heather.

Light fires and disposable barbecues have no place on heathland — dry gorse and grass burn fast and the damage lasts decades. Take everything home, including fruit peel, and use the bins or carry it out. Tread lightly on the shingle above the strandline, where ringed plover and little tern scrape out their nests in the stones. Do that, and the reward is a coast that keeps its drama, its quiet and its wildlife for the next walk, and the one after that.