A seven-year-old child swimmer stopped breathing after getting into trouble during its annual Summerfest at a Canterbury fee-paying school.
The distressed youngster vomited before being pulled to safety and revived, a court has heard.
He was one of a number of children who attended the three-day event at the independent St Edmund's School at St Thomas' Hill.
But during a swim, the youngster lost a swimming flotation aid and floundered for four minutes before going under.
Now a judge has heard that although there had been three lifeguards on duty that day – only one of them had a current safety certificate.
The school has now been fined £18,000 after pleading guilty to a charge under Health and Safety regulations of failing to discharge its duty.
Prosecutor Matthew Butt told Canterbury Crown Court: “There was clearly not a sufficient level of vigilance.”
The incident was caught on CCTV and played to Judge Heather Norton – as the child’s weeping mother sat in the public gallery.
The prosecutor added:“One of the events of the three-day festival was youngsters using the heated outdoor pool.
"Three lifeguards were on duty, two of them sixth formers and the third in his first year at university.
“None of them was asked by the school to provide proof of their qualifications, “ he added.
Mr Butt said two of the lifeguards’ qualifications had expired and they should not have been working that day.
“The concern is that no checks were made by the school, “ he added.
The court heard how the child was “not a strong swimmer and had only recently learned to swim without armbands.”
Mr Butt said the school did not know of his proficiency in the water – but claimed it had made requests for the data from the child's parents.
The CCTV footage was then shown to the court after Judge Heather Norton asked if the boy’s family preferred to leave court during it being shown.
The child was later taken to the William Harvey Hospital and kept under observations for 24 hours and has now been left with a fear of water.
Mr Butt said the child’s mother suffered psychological effects including post traumatic stress as a result of the near tragedy.
Dominic Kay, defending, said: “It is a source of significant regret that this school finds itself in court over issues of safety. It’s a school which prides itself on its systems, policies and procedures.
“The school has an exemplary safety record and it’s head and governors wish to express their genuine remorse and regret to the court and to the boy’s family over this sorry incident.”
Mr Kay added: “It goes without saying that he should have been spotted before he was but we don’t accept he was in distress for four minutes and these were competent lifeguards.”
The court had earlier heard that, at 3pm on August 1 2014, there had been 30 children in the pool enjoying “a free swim” when the youngster loses his float.
The prosecutor said: “He was in difficulty from that moment onward and that difficulty becomes increasing pronounced and increasingly obvious as time goes by.
“He struggles for several minutes becoming increasingly distressed and desperate.”
Mr Butt said he then became submerged three minutes into his swim- with both his arms going up and “plainly sinking into the water”.
The court heard how the youngster then vomited under water as one of the guards realised there was an emergency and jumped into the water to rescue him.
“Once he is pulled to the side of the pool, it is obvious he is not breathing and is given artificial respiration both in and out of the pool, seven or eight breaths.
“The boy splutters, water comes from his lungs and he starts breathing, “ the prosecutor added.
The judge fined the charity school £18,000 – which was equal to its profit from the last financial year and allowed it to be paid over three years.
Judge Norton said: “Two of the guards should not have been working but of itself did not expose the child to risk or have a causative effect on what happened.
“The risk is that the school failed to ensure the lifeguards held the relevant qualification – it could not be sure the guards had any experience or competency at all.
“In my view this was a serious failing"
She added: “The incident with this child makes it quite clear it does not take long for a child to go from being in difficulty to being in danger.
“It should not take a potentially catastrophic incident to ensure high levels of vigilance around a pool with many children.”
A statement from the school said after the sentence: "We accept in full the findings of the judge, that while there were administrative shortcomings, these in no way contributed to the incident.
"The School sincerely regrets this incident and has taken the measures necessary to ensure its H&S procedures are maintained at their most effective levels.
"An external assessment, policy update, (noted as excellent in the recent ISI inspection report, item 4C) and the appointment of a Health & Safety Manager have continued and enhanced the ongoing development of a proactive health and safety culture at the School."
The school was also ordered to pay £9,670 costs.