Swim survival lessons in which toddlers and babies are dropped into the water have been criticised by experts as “harmful” and “distressing”.

While there are many restrictions like reducing chemical usage, installing heat pump water heater for pool, adding automatic pool filters, and many more, differences of opinion might arise when it comes to swimming classes for toddlers.

Swim England and the Royal Life Saving Society UK are among organisations warning parents against classes that aim to teach young children to rescue themselves by rolling on to their backs in water.

YouTube videos from the United States show toddlers being taught how to avoid drowning and critics say the children are distressed. Similar classes have arrived in Britain.

Emma Aspinall, 33, launched her own swim survival lessons after her son Loui, two, drowned in 2013 after wandering alone into a pool during a family holiday to Tunisia. She found a programme in America teaching children to “self-rescue” and raised more than 10,000 to complete the course herself.

Determined that Loui’s death would not be in vain, she researched children’s water safety courses before completing her training and now teaches at a fitness centre near her home in Wigan. After criticism of a video she shared online of a boy crying during a lesson, she defended the technique, saying: “Don’t kids cry for lots of reasons? It doesn’t necessarily mean there is something wrong. They cry when we take them for vaccinations but we still do it.”

However, water safety organisations and the teaching groups Puddle Ducks, Turtle Tots, Birthlight and Water Babies have criticised the practice. A spokesman for the coalition of groups said: “These sink or swim methods promote the derisking of drowning accidents for toddlers through classes in which learners are taught, and forced, to roll on the back to float.

“While some may see this highly stressful, forceful method of teaching as being a means to an end, the wider baby swimming profession argue that there is a need to examine if these drown-proofing techniques, which are being promoted to parents as insurance for their child’s water safety, are actually safe, acceptable and effective.”

Françoise Freedman, a medical anthropologist at the University of Cambridge and an expert on baby swimming, has written a critical report, Sink or Swim, Drown-Proofing Teaching Methodologies. She said: “[Forcing] a baby or toddler to float relies on extreme traumatic methods and, sadly, no amount of praise will compensate for the memory of inflicted pain – it just gets pushed into the recesses of our brain, where it is recorded.” She added that for some children such “trauma” could lead to a fear of water.

Paul Thompson, co-founder of Water Babies, said: “We are aware of the distress to children the self-rescue technique can cause and regard it as an aggressive, unproven method to make babies ‘drown-proof’ .”

Mrs Aspinall is undeterred. She said her lessons were “taught one-to-one, not in a group of up to 12 like traditional swimming lessons”.

She added that she knew of five such classes in the UK, and that the technique had been practised in the United States for more than 25 years. It was also taught in South Africa and Australia. Mrs Aspinall began teaching in April and said her students were a testimony to the effectiveness of her programme.

“One of my four-year-old students went on holiday and slipped into the pool and instantly got on to her float position,” she said. “She had only had three weeks of lessons but was able to save herself. I have never and would never say this method is drown-proofing because that is impossible. So those making that statement are lying. This just gives extra protection.

“I would also like to see evidence of the so-called children that have been affected badly later on in life by these lessons. I have videos that show the kids happy in their lessons.”

Lesley Jalloh, 33, a carer from Wigan, is an advocate of Mrs Aspinall’s classes. Her son Matthew, two, is shown crying in a swim survival video but she said: “It’s saving lives. It’s teaching children to float on to their back rather than going into the water panicking.”

Rival techniques

Dunking As simple as it sounds. The baby is held and briefly dunked under water before being lifted out. The process is then repeated a few times. Some methods involve dunking the whole head beneath the water.

Gentle splashing Some parents prefer to ease their baby into their surroundings by gently splashing them and trickling water over their head. This can escalate to blowing bubbles and letting them float on their backs while holding them, so that their ears are in the water.

Swim survival or “drown-proofing” This controversial method involves children learning how to swim by being put into the water. The idea is that they teach themselves how to stay calm, get on to their backs and keep their heads afloat.

Pillow The parent goes into the pool with the baby, whose head is placed on to the parent’s shoulders like a pillow. The baby is gently moved downwards so that they are floating and the parent’s hands are moved away from the baby’s head. The parent then alternates holding the baby’s head with their right and left hands to get them used to the water.