The organisation of a rugby trip to the south of France during which a British teenager drowned in a lake was "inadequate" and "slipshod," an inquest has heard.
Harry Sykes, 16, was travelling with the Halifax Elite Rugby Academy when he died while swimming near Carcassonne in 2018.
An inquest into his death, held at Bradford Coroner's Court, heard he was not reported missing until his team returned to their hotel.
The group went to the beach and Harry swam to some rocks and joined in a volleyball game at around 2pm in the shallow section.
His body was found in 6ft 6in (2m) of water in Lake Cavayere - 66ft (20m) away from the beach.
Recording a narrative conclusion, West Yorkshire senior coroner Martin Fleming said there were "significant flaws" in the organisation and preparation of the visit to the lake.
He said: “This resulted in confusion and uncertainty with respect to supervision, which was at best sporadic.
“The lack of head counts showed significant flaws in supervision and enabled Harry to disappear.
"Harry suffered a cardiac event of uncertain origins while swimming and drowned in unclear circumstances when not observed to have been in difficulties."
Mr Fleming said nobody had noticed Harry was not in a group photo taken before they left.
And a "cursory" check of the beach had failed to alert them that Harry's bag and towel were still there.
The inquest previously heard the teenager was last seen alive in the water at 1.30pm on 5 September 2018, but he was not reported missing until around 6pm.
The French authorities were contacted and divers were later dispatched.
Harry's body was recovered from the lake that evening and he was declared dead at 10.45pm.
Mr Fleming added it remains unclear whether there would have been a different outcome if Harry had been seen and retrieved from the water.
He said he was unable to find an unlawful killing conclusion, but branded the organisation of the trip to the lake inadequate and slipshod.
Mr Fleming said brothers Lee and Gareth Greenwood, both former professional players who founded Halifax Elite Rugby Academy, were in breach of their duties.
He said the company failed to plan the group's trip to the lake properly and to supervise the boys properly at times on the day.
It had also failed to conduct headcounts of the group, aged between 16 and 19, during the trip.
Mr Fleming told the inquest: "Harry's life was cut short by this terrible tragedy."
Speaking after inquest, Harry's mother Natasha Burton added: "We are astounded that, yet again, justice has not been served for Harry.
"This is a tragic and unnecessary death. The coroner himself said the organisation and preparation of this trip was inadequate and slipshod with only sporadic supervision.”