My coastal packing list is different from my general one, and nearly every item on it earned its place by being missing at an inconvenient moment.
Wind is the actual weather
The thing people get wrong. They pack for the temperature and the coast is about wind.
A windproof outer layer matters more than a warm one. Wind strips heat far faster than still cold air, and a fleece in a coastal wind is close to useless while a thin windproof shell over it is transformative.
Something to hold a hat on, or a hat that will not blow off. I have lost two.
And sunglasses that stay on, because coastal glare is severe even on grey days and the wind will take loose ones into the sea.
Salt gets into everything
An effect that is stronger than I expected before I started going regularly.
Salt spray carries a long way inland on a windy day and coats everything — clothes, bags, glasses, and anything with a lens or a hinge.
The practical consequences: a microfibre cloth, constantly. A dry bag or at least a sealed plastic bag for anything electronic. And rinsing things in fresh water at the end of a day rather than at the end of a trip, because salt left on metal does real damage.
Zips are the specific casualty. A salted zip on a bag or jacket seizes, and once it has corroded it does not recover. Rinsing and drying zips is a two minute job that has saved me a rucksack.
Footwear, which is the item people get most wrong
Three kinds and each does a job the others cannot.
Something that can get wet and dry fast, for the beach and for anywhere you might be in and out of water. Not flip flops, which are useless on rocks and lost in waves.
Something with grip for wet rock, which is a specific and unforgiving surface. Wet rock covered in algae is among the most slippery things anybody walks on, and ordinary trainers are dangerous on it.
And something dry and comfortable for the evening, kept away from the other two.
Sand in shoes ruins them slowly. A brush or even a strip of tape to lift sand out is worth carrying.
Sun exposure is higher than it feels
The combination that catches people. Cooling wind removes the sensation of burning while reflection off water and sand increases the dose.
People burn badly on cool windy coastal days and are surprised, because they associate burning with feeling hot.
What I carry: a high factor sunscreen in a larger quantity than seems necessary, because it needs reapplying after wind, water and sweat far more often than a label suggests. A long sleeved light layer, which does the job better than any cream. And lip protection, which everybody forgets and which is exposed constantly.
The things that are specifically coastal
A dry bag. Not for boating — for carrying a phone and a wallet to a beach where you want to swim and there is nobody to watch your things. Also keeps sand out, which is a bigger benefit than the water protection.
A towel that packs small and dries fast, since a wet cotton towel in a bag stays wet for the rest of the trip.
A cheap pair of goggles, which turn a swim into something you can look at.
Waterproof plasters, because cuts from rock, shell and barnacle are common and ordinary plasters fall off immediately.
And a small torch, because coastal paths in the dark are more consequential than urban streets in the dark.
What I stopped carrying
Beach umbrellas and anything that catches wind, which are unusable on most of the coasts I visit.
Elaborate beach equipment, which is heavy and used once.
Books that matter to me, because paper and salt air and sand are a poor combination.
And a large towel, replaced by the small quick-drying one, which took a while to accept and was correct.
The one thing I would not travel without
A second set of dry clothes kept in a sealed bag, entirely separate from everything else.
Coastal days go wrong wetly. A rain squall, an unexpected wave, a slip on a rock, a swim that was not planned. Having something genuinely dry to change into converts a ruined afternoon into an anecdote.
It takes up very little room and it is the single item I have been most grateful for, on at least four occasions I can specifically remember.
The electronics problem
Worth a separate note because it is where the expensive damage happens.
Sand in a charging port is difficult to remove and can prevent charging entirely. A phone that has been on a beach should be checked and blown out rather than plugged in blind.
Salt air corrodes contacts slowly, which is a problem on longer trips rather than a week.
And heat is underestimated. A phone left in the sun on a towel will overheat and shut down, and repeated overheating damages batteries permanently. Keeping it in a bag in shade costs nothing.