Aidan Sands, who could not swim, died aged six on 18 June 2011 during a trip to the leisure centre at the Red Lion Caravan Park in Arbroath, Angus.
The park’s operators, Loch Earn Caravan Parks Ltd, was yesterday fined £234,000 over health and safety failings that led to the tragedy.
Forfar Sheriff Court heard that Aidan, of Dundee, his mother and three siblings had arrived at the park three hours before the tragedy for a short break.
He had been playing in a toddler pool with his brother while his mother and two sisters swam in the 1.2 metre deep main pool.
Aidan then made his way into the main pool with a tubular float, but lost grip of it and was submerged.
Speaking outside court, Aidan’s father said: “This has ripped our family apart.”
Fiscal depute Gavin Callaghan told how Aidan’s brother was the first to notice the unfolding events.
He said CCTV captured the boy going underwater for 51 seconds before he was pulled to the surface, dragged from the pool and had CPR performed on him by other swimmers. The pool had no lifeguards and staff were not trained in CPR.
Aidan was rushed to hospital but died four days later from brain injuries caused by his near-drowning.
Mr Callaghan said: “As he held on to the pool edge the tube floated away from him.
“He reached out to grab it but missed, causing his head and body to go under water.
“This was not noticed by anyone else at the pool at that time.
“About 51 seconds later Aidan’s brother became aware that he was under the water and pulled his head above the surface.”
He added: “Had the lifeguarding provision been in place on the date of the incident, intervention would have taken place before the tragic consequences were allowed to develop.
“The provision of lifeguards would have reduced the likelihood of the incident occurring and the failure to have lifeguards in place is therefore a significant causal factor in the resultant death.”
Loch Earn Caravan Parks Ltd, based in Errol, Perthshire, pleaded guilty on indictment to charges under the Health and Safety at Work Act.
Sheriff Jack Brown imposed a fine of £234,000, reduced from £350,000 for the guilty plea.