Despite its being a legal requirement of the national curriculum, one in 20 primaries fails to offer swimming lessons during school time. And of the schools which do take children swimming, one in nine fails to teach more than half of their pupils to swim 25 metres by the age of 11.
Cuts in school budgets, combined with the cost of school transport, pool time and specialist tuition have led almost half of primary schools to ask parents for a contribution towards lessons.
Schools say the pressures on lesson time means many of them cannot find the time to take children to their local pool which can be up to an hour's drive away.
"We are seeing a deplorable decline in school sport and swimming in particular, largely as a result of the enormous pressure on schools to deliver the core subjects and the pressure on school budgets," said David Hart, general secretary of the National Association of Head Teachers. "Children are missing out on swimmin which everyone regards as a crucial skill."
The TES survey of 769 primary schools across the UK found that more than a quarter keep no record of pupils' achievements. No official figures are kept on the success of school swimming, although records in teaching swimming will come under official scrutiny when a year-long investigation by the Office for Standards in Education is published in September.
Under the national curriculum all schools in England are required to help pupils meet specific targets - including swimming 25m unaided.
However, the survey also suggests that English children seem to fare no better or worse than their counterparts in the rest of the UK, where swimming is included in the curriculum but no targets are set.
Nigel Hook, spokesman for the Central Council for Physical Recreation - an umbrella body which represents teachers' unions and sports governing bodies as members - said: "The end-of-year report on school swimming makes depressing reading.
"All four million children in primary school should be taught to swim. These skills can save children's lives."