Swimming has been a compulsory part of the national curriculum for more than 20 years. Yet, hand on heart, I doubt a larger proportion of primary school children can swim well now than could two decades ago. And by well, I mean well enough to cope with a sudden fall into a river or to tread water in the sea.

It’s not the lack of Olympic potential I’m worried about, but an absence of basic water skills.

Why, you may ask, are almost a third of kids - 250,000 nationally, according to our estimates - leaving primary school each year unable to swim well?

No one seriously doubts that it’s an essential skill, which is why schools are required to devote a small part of the curriculum to teaching youngsters how to swim, and why the government gives them funds for it.

Indeed, water safety is the only part of the national curriculum that saves children’s lives. It shouldn’t be treated as an optional extra. But all too often it is. So what has gone wrong?

It’s too easy to blame schools. They can point to the increasing curriculum and accountability pressures and the many claims on their time.

Many schools don’t realise, however, just how easy and relatively inexpensive it is to equip children with these life-saving skills. To teach a youngster to swim before he or she leaves primary school costs just £80 per head on average.

Teachers lack swimming confidence

Swimming confidence among teachers is a bigger obstacle. At the moment there is no statutory requirement for teachers to be trained to the necessary standard. And only 11 teacher-training colleges include swimming in their curriculum. So it’s understandable if some teachers lack the confidence to teach the subject.

But lack of proficiency shouldn’t be an insurmountable problem. If a teacher feels they lack the skills, we can recommend short courses to remedy any deficit.

If it’s a question of polishing or expanding existing skills, there are plenty of free resources available. And if teachers prefer to rely on external help, there are swimming experts in every area of the country.

Money or skills shortages are not fundamentally to blame for our failure to teach a quarter of a million primary school leavers how to swim properly. So what is? In short, schools aren’t taking swimming seriously because they aren’t being pushed to do so by Ofsted.

Some inspectors do assess schools on their swimming responsibilities. But too few ask to see evidence, even though it is a simple to check if schools have complied with the minimum requirements.

If Ofsted were to make it clear that inspectors would routinely judge swimming provision, the response from schools would be immediate. They would not be tempted to neglect swimming if it meant they risked a bad inspection. And as a result, many more children would leave school equipped with the skills they need to keep them safe. 

Few solutions in education can be described as a silver bullet. But I believe getting Ofsted to take its swimming responsibilities seriously is one of them.

If it acts, and does so urgently, I believe many more children will have the water skills their parents expect and they deserve.

Steve Parry is an Olympic medalist and chair of the Curriculum Swimming and Water Safety Review Group

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