Swimming is not being taken seriously enough by primary schools, with many failing to teach youngsters how to swim properly or to stay safe in the water, according to a report.
Under the national curriculum for England, primaries are required to teach pupils how to swim at least 25 metres, the length of an average sized swimming pool, how to use a range of strokes, such as front crawl and backstroke, and how to perform safe self-rescue in different situations.
But a report by the Curriculum Swimming and Water Safety Review Group, concludes just over a third (36%) of primary schools provide lessons, with all children achieving the national curriculum targets.
It suggests there are a number of barriers to schools offering proper swimming and water safety instruction, including teachers not feeling confident in teaching the subject because they lack formal training, the cost of transport and hiring pools and swimming instructors and concerns that time away from the classroom disrupts the school day.
The Group also warned that swimming is not being properly enforced, with anecdotal evidence that the subject is being sidelined by schools who prioritise subjects that they are graded on.
In a foreword to the report, which has been submitted to government, review group chair Steve Parry said: "The inclusion of swimming within the national curriculum means there is no excuse why any child in this country should not be able to swim.
"Even those children who are unable to go swimming with their families have the opportunity to learn how to swim. It is fool-proof: every child goes to school therefore every child is taught how to swim.
"Except the data over the last five years suggests otherwise. The number of our young children at primary school who can swim remains around the 50% mark. This is unacceptable."
A poll conducted as part of the report suggests that almost a third (31%) of parents of 10 and 11-year-olds, those in the final year of primary school, have children that are unable to swim at least 25 metres, while just over a third (37%) say their youngster can perform safe self-rescue
The review group makes a series of recommendations including training and resources for teachers, a new national swimming programme for schools and achievement badges for pupils meeting national curriculum requirements.
Mr Parry, an Olympic bronze medal-winning swimmer, said: "At the moment we are failing our children by not helping them learn an essential skill.
"Hundreds of people drown ever year and that is something we can remedy."
Children's Minister Robert Goodwill, said: "Swimming is a vital life skill and schools have a duty to teach children how to swim and learn about water safety at primary school.
"These findings show that more needs to be done to ensure all schools feel confident teaching swimming to students, which is why we will continue to work closely with Swim England and the Swim Group to review the recommendations within this report."