Sea cliffs, islands and open water

Sea cliffs form because the sea washes out the base of the rock. Waves hurl water and stones against the wall until a notch forms. Eventually the rock above hangs without support and breaks away. Rain seeping into cracks and frost expanding the water in them loosen the rock even further. Collapses are therefore a natural, ongoing process – and so they cannot be predicted.

What makes it especially treacherous is that the edge can look solid from above even though it is already undercut. Grass and soil can lie like a roof over a hollow. After rain, in wet conditions and in strong wind, the risk rises that parts give way or that you slip.

On the water another factor comes in: water draws heat from the body much faster than air does. People who fall unexpectedly into cold water often react with a sharp gasp and rapid breathing – known as cold shock. At that moment it is easy to breathe in water.

Stay on the paths, respect barriers and warning signs, and do not go to the edge for photos. Hold children by the hand and keep dogs on a lead – a dog chasing a bird or a ball notices the edge too late. In wind, wet weather and after rain, keep even further back than usual.

Down on the beach something else applies: do not rest directly below cliffs, because rockfall can strike there. Check the tides before walking along the water below cliffs. The incoming tide can cut off your way back, and a steep rock wall offers no way up.

In an emergency on the coast or at sea, alert the local emergency number (112 in the EU) or the coastguard. At sea, VHF marine radio is the usual way to send a distress call; using it requires its own training and licence depending on the country. Before every boat trip, tell someone on land where you are going and when you plan to be back.

If you are on an island, you depend on ferries, boats or flights. Storms, fog and rough seas can interrupt these links for hours or days. So do not plan on the last ferry of the day but with a buffer – a missed appointment is annoying, a risky crossing in a storm is dangerous.

Take medication you need regularly for a few more days than planned, as well as some extra supplies. Small islands often have only limited medical care, and a rescue transfer can depend on the weather. Follow the weather forecast and the ferry operator's notices.

If you fall unexpectedly into the water, do not fight the waves straight away. The British lifeboat charity RNLI advises first lying back and floating until your breathing has calmed. After that you can think more clearly, shout or wave for help and move towards something that floats or towards the shore.

A lifejacket keeps you afloat without any effort of your own – exactly when cold shock takes away your control. That is why you wear it on small boats rather than just having it on board. Carry means of communication such as a phone, radio or distress beacon in waterproof packaging.

Distress signals at sea are regulated internationally, in Annex IV of the collision regulations. That way every ship understands that someone needs help. Anyone who wants to skipper a boat or use marine radio needs training and often a licence, depending on the country – this text does not replace seamanship.

Most hazards on sea cliffs are easy to avoid with distance and planning. If you stay on the path, know the tides, allow a buffer for ferries and wear a lifejacket on the boat, you can enjoy the coast in peace.