The dad of a "beautiful" six-year-old described watching on helplessly as the boy drowned in a river.
Lucas Dobson had been spending time with his father and friends near the River Stour at Sandwich in Kent when he got into trouble in the water on Saturday August 17 last year.
He was playing with other children on the river bank when he fell into the water between a jetty and a moored boat, the inquest in Maidstone was told.
His father, Nathan Dobson, told the hearing that he was working on one of a number of vessels by the river, while his friend James Fromage was cooking on a barbecue and another friend, Pete Snelson, was fishing nearby.
Lucas tried to climb on to one of the boats with other children who were playing.
Fighting back tears, Mr Dobson told the inquest: "I looked down for less than a minute, and then I heard a commotion.
"I stood up and saw the look on James' face, and he said it was Lucas.
"Before a blink of an eye they were in the water looking for him.
"I saw James and Pete get in the water and I looked which way the current was going and I went a few boats up to jump in the river."
Mr Fromage, at whose riverside property the boats were moored, told the inquest he had seen Lucas attempt to climb between the jetty and a boat.
He said: "He went for the rail [of the boat] and lifted his foot and missed the rail and dropped, straight in feet-first.
"I dropped the barbecue tongs and jumped down to try and grab him, but I could not get in the gap between the boat and the mooring."
Recollecting the conditions in the river that afternoon, Mr Fromage told how the "surprisingly strong" current had carried Lucas away from the spot where he was last seen falling into the water.
None of those present when the accident took place, including Lucas, were wearing lifejackets or other safety equipment, the hearing was told.
Despite searching frantically for some time, the friends were unable to find Lucas and the emergency services were called.
A massive search began for Lucase, who lived in Deal, Kent, involving hundreds of local residents who joined expert volunteers from Kent Search and Rescue.
Two days after he disappeared, Lucas' mum Kirsty Furze led hundreds of well-wishers on a candle-lit walk to the end of Deal pier.
The family's plight prompted a wave of support from people in coastal communities and several vigils were held.
The boy's body was found, four days after he disappeared, on Wednesday August 21, close to where he went missing.
A post-mortem concluded the cause of death was immersion.
Area Coroner Joanne Andrews delivered a verdict of "accidental death."
Following the hearing, a statement on behalf of Lucas's mother Kirsty was read by solicitor Neille Ryan.
He said: "Lucas Dobson was a beautiful, popular vibrant six-year-old boy.
"He loved singing, dancing cars and bikes.
"His loss has had a devastating effect on the family, so much so that Lucas' mother Kirsty could not face being here today.
"The events which led to Lucas' death were entirely preventable.
"The family are devoting all their efforts to ensure that Lucas' death brings greater awareness to safety on the river, greater care and attention is taken when children are present and that buoyancy aids are always used."
