The list writes itself by about the third day of a Devon holiday. Windbreak, towels, sun cream, a cool bag with more in it than anyone will eat, buckets, a change of clothes for whoever ends up in the sea fully dressed. Most families get very good at this very quickly, and the boot of the car starts to look like a small expedition.
What people underestimate is enough water for everyone, all day, in something you'll actually carry. It sounds like the least interesting item on the list until you're halfway back up a coast path in the afternoon sun with two children, an empty bottle and a beach café that closed at four. Devon's better beaches often involve a proper walk from the nearest car park, and that walk is a lot longer on the way back.
Why a good travel water bottle beats buying as you go
Buying drinks as you need them works fine in a town and falls apart on a beach day. The remote coves have no shop at all, the ones that do have a kiosk close earlier than you'd expect out of season, and the queue at the only van in Woolacombe on a hot August Saturday is its own form of holiday.
A good travel water bottle removes the whole question. Stainless steel bottles from ranges stocked by retailers like Notino hold their temperature for hours, which matters more than it sounds when the alternative has been sitting in a hot car since ten in the morning.
What actually matters in one you'll carry all day
Insulation first. A double-walled steel bottle filled with cold water in the morning will still be cold at four, and the same bottle keeps tea hot for a windy walk in October.
Then the seal. Anything going into a rucksack with towels and phones needs a lid you trust completely. Then capacity: one large bottle is easier to carry than three small ones, though a smaller one per child usually keeps the peace. Steel also avoids the plastic taste that puts children off drinking in the first place, which is half the battle on a hot day.
Where to fill up
Devon has a decent network of free refill points, with cafés, pubs and visitor centres across the county signed up to the national refill scheme and happy to top up a bottle whether or not you're buying. Most of the larger beaches have public taps somewhere near the toilets, and holiday parks and campsites will always oblige.
Fill everything the night before and leave it in the fridge. It's a small habit that removes a decision from a morning that already has plenty.
The beaches where it matters most
Anywhere with a long walk in. The South West Coast Path stretches for hundreds of miles along both Devon coasts, and some of the finest stretches of sand sit at the bottom of a steep descent with nothing at the end of it. The same goes for the wide beaches of the north coast, where the walk from car to water can be a fair distance.
Get the water right and everything else on a beach day is negotiable. Get it wrong and you'll spend the last hour of a good afternoon thinking about a tap.