Cole Moreton: You can keep Ibiza. Nothing can compare with the British seaside

Summer half-term is once more upon us, and a perfect day at the beach beats Disneyland hands down – but do watch where you swim

(TOM PILSTON)

Holidays are here again, so let's take down the Union flag and run something else up the pole for a change – a good old multicoloured British nylon windbreak.

We should fly it proudly at this time of year, because the windbreak is a symbol of national spirit as potent as the Stars and Stripes on the Moon. The windbreak says: "Here we are, however bad the weather, however daft we look, and we shall not be moved."

We all have chilly memories of huddling behind one, wrapped up in coats over swimsuits, chewing on sand sandwiches, because the windbreak represents one of the great British obsessions – A Day at the Beach.

I don't mean the sunny, sandy shores of somewhere foreign like Ibiza, to which our Prime Minister has fled on easyJet. How envious he must have been, in retrospect, of Air Force One. And how long do you think it will be before he and Sam are sipping cocktails in the Caribbean with Sir Cliff? But I'm talking about the native kind.

A third of all Britons are planning to take their breaks in the British Isles this year, according to a survey by Travelodge (well, it wasn't going to be Club 18-30) and a third of those will spend their "staycation" at the seaside, as the Camerons have done in the past. Our PM is turning his back on British beaches just when there is some very good and significant news about what's in the water.

The Marine Conservation Society has just published its annual Good Beach Guide and declared: "Our bathing waters are at their cleanest for two decades."

The Society gives top marks to 461 beaches. Among the best places for bathing are Polzeath in Cornwall, Portobello Central in Edinburgh and Tenby in Pembrokeshire. I'm very pleased to find myself 10 minutes' drive from two of them, in East Sussex, having followed a lifelong urge to be by the sea. After years in East London, I finally made the break for the coast with my family a few years ago.

The change was dramatic: our asthmatic, indoor children became wild, healthy beach bums breathing in clean air. And there is something very calming about resting your eyes on the horizon, under a wide sky, with the colours shifting on the waters. That's why you'll find some of us out there whatever the weather, enjoying beaches at their empty best out of season. But the sense of space and freedom is also one reason why people head for the seaside in such numbers at bank holiday time.

You've just got to be careful where you swim. I'm always wary of the brown scum in the Channel, and the jellyfish shoal that turns out to be plastic bags. Thousands of volunteers take part in a Beachwatch big clean-up every autumn, and last year they removed 330,000 bits of rubbish. The disgusting truth is that it doesn't all come from ships: we're flushing more and more waste like cotton buds, sanitary towels and condoms down the toilet – but it is not caught by the sewage filters and so ends up in rivers and on beaches.

There are 22,000 "combined sewer overflows" around the coast, which operate when there is heavy rain but at other times too. The Marine Conservation Society wants every one to be mapped and monitored, so we know when to avoid swimming anywhere near them. This year it has failed 46 beaches completely, and left them out of the Good Beach Guide, because the waters contained "excessive levels of human sewage and waste from animals". Go for a dip in those places and you risk a stomach upset, an ear, nose or throat infection, or worse.

This is no idle threat. The Good Beach Guide began in 1960 as a list of safe places to swim, compiled by a couple who had lost their daughter to polio. Caroline Wakefield became ill after swimming in waters where raw sewage was being pumped. She was six years old. Her parents, Tony and Daphne, joined a campaign that led to new European safety laws in 1976, and those standards are to be more rigorously enforced after 2015. After that, offending beaches will have to display signs warning people not to swim.

I bet they still do, though. After all, beaches are among the few places left where you can take risks undisturbed. Even if the flag is red, the waves are massive and the tide is strong, most of the time there won't be anyone around to stop you getting in the water. Yes, the undertow may rush you and your lilo out into the shipping lane, to be cut down by a supertanker, but at least health and safety won't be there to stop you. Lifeboat crews may grumble at having to chase stray inflatables or haul the corpses of idiots from the water, but they keep doing it, bless 'em.

Perhaps a better reason for going to the beach is that it's cheap. Staycations can be really expensive. Taking a family of four to Legoland for the day will cost over £100, Alton Towers more. Even our local zoo will charge close to a ton for letting the little ones see a couple of meerkats and a weary looking llama. The beach costs nothing. You don't have to queue for hours for a 30-second ride, either.

The downside of the sheer bloody-minded defiance symbolised by the windbreak is that the British will often put up with any kind of hell in their determination to be seen having a good time – whether that's a picnic by the side of a motorway jam, chewing on overpriced cattle fodder at a service station or standing in line with moaning children so they can go on a rollercoaster and be scared witless. Again. Most British days out leave you bankrupt and exhausted. Not the beach. If it all gets too much, lie down and listen to the waves.

There's also nowhere finer for people watching. Start a game with extra points for spotting the elderly woman who is barely able to walk across the shingle, but enters the water without breaking the surface and swims like an Olympic champion. Or the Bully Dad who rushes into the water, hurling insults at his reluctant children – only to rush straight out again.

They are all chasing a dream. The myth of the perfect British summer beach day, just like the ones we used to have when we were kids and the school holidays went on forever and the sun was always shining. You know: finding a crab in a rockpool, fishing with a net, laughing in the surf, building sandcastles, drinking Dandelion and Burdock on a tartan rug. We ignore the less pleasant memories – cutting a toe on a rock; biting into a sandwich and being stung on the mouth by a wasp; running from psychotic seagulls; getting sunburn, and sand "in your parts", as my mum used to say. Why? Because sometimes – just sometimes – the clouds part and the sun comes out. The wind dies down. The sea is calm and clean. The dream comes true.

We were in Dumfries and Galloway over Easter, and the weather was amazing. Hot enough to lie in with only a T-shirt, which is a near miracle on the Solway Firth. Yes, the water was cripplingly cold, but the sunshine took everyone by surprise. As a friend, who is a local, said: "You could wait for 10 years and not get a day like this." But we had several, in a row, and it was perfect. Far better than Ibiza.

On days like those, give me a wide open beach, with water to paddle in, rocks to play on, space for cricket and a place to erect a good, sturdy windbreak (and some warm clothes, a mac in case the weather turns, oh, and a Thermos flask of hot tea) and I am perfectly happy. It's beautiful, it's natural, it's fresh and wild and open and costs nothing. When it all comes right like that, the great British beach beats Disneyland every time.

Cole Moreton is the author of 'Is God Still An Englishman? How we lost our faith (but found new soul)' published in paperback this week by Abacus