Former Harrow schoolboy, 25, died after diving into the water following a heavy consuming session – together with his physique not being discovered for days afterward

A former schoolboy at one of Britain’s top public schools drowned in the Norfolk Broads after diving into the water following a heavy drinking session with an old school friend.

Henry Keith, 25, who attended £61,500-a-year Harrow School in north-west London, disappeared under the water during the late-night dip, despite being a strong swimmer.

A coroner concluded he may have banged his head while going into the water at Wroxham Broad on August 16 last year. His body was found nearby two days later.

Sebastian Cator, a captain in the Royal Logistics Corps, told the hearing how his friend had undressed and entered the water headfirst.

But he failed to resurface after diving off the rear of a launch that belonged to his father, just after it slowed to a halt.

The Old Harrovian said he heard a ‘scratching or tapping’ noise on the underside of the boat, adding: ‘My immediate reaction was that he was trying to play a prank on me. I walked around either edge of the boat and could not find him.

‘That was when I realised he was not playing a joke and began to panic.’

Mr Cator described how he called frantically for his friend – a director at the Organic Pig Company, which was founded in 1998 – but called emergency services after getting no response, leading to a large, multi-agency search.

Henry Keith, 25, who attended £61,500-a-year Harrow School in north-west London , disappeared under the water during the late-night dip, despite being a strong swimmer

Henry Keith’s family issued an emotional tribute to him after the inquest, saying: ‘The loss of our precious Henry has created a huge void for our family and all the many friends who loved him dearly’

Mr Keith’s body was recovered from the water in an ‘upright position’ just beneath the surface on August 18.

Mr Cator told Norfolk Coroner’s Court in Norwich of his heartache and regret about events leading up to the loss of one of his closest friends, explaining how he constantly replayed what had happened in his mind.

Asked by Mr Keith’s brother, Edward, why he didn’t jump in to look for him, he said: ‘I wanted to and I do not know why I did not. Maybe I should have done and I can only apologise for that.’

However, he added he would have been better able to help his friend from the boat if he had resurfaced.

Norfolk area coroner Yvonne Blake recorded a conclusion that the death was an accident.

But she accepted questions remained about how he came to drown when he was known to be fit and a strong swimmer.

‘He could have knocked his head on something under the water, which could have stunned him,’ she said.

The pair, who went shooting together, had begun drinking at around 3.30pm at the Swan Inn pub in Horning before heading to Mr Cator’s family’s home nearby.

Harrow School was founded in 1572 and the official uniform includes morning suits and Harrow Hat – made of varnished straw with a blue band – which are worn on Sundays

They had a total of five bottles of Becks lager each, as well as a bottle of rose and a bottle of white wine at dinner, then vodka and ginger beers on the boat, where they listened to music before deciding to go for a swim before midnight.

A post-mortem examination found Mr Keith had 185mgs of alcohol per 100ml of blood – more than twice the legal limit to drive.

His family issued an emotional tribute to him after the inquest, saying: ‘The loss of our precious Henry has created a huge void for our family and all the many friends who loved him dearly.

‘He was a caring and cheerful young man with a bright future ahead of him.’

The family thanked emergency services involved in the search for him, particularly the Hemsby lifeboat and Norfolk Lowland Search and Rescue.

They added: ‘These two organisations did not rest for a moment until he was found.’

In an earlier tribute, posted with a notice of his funeral, they said: ‘Truly he was a gift from God, taken back on a golden summer day.’

The statement described him as a ‘beloved son’ of James and Vicky and an ‘adored brother’ to his four siblings.

It added: ‘The most wonderful, unique, charming and brilliant young man, universally adored. Rest in Peace darling Henry.’

Harrow School was founded in 1572 and the official uniform includes morning suits and Harrow Hat – made of varnished straw with a blue band – which are worn on Sundays.

Former pupils include seven former British prime ministers including Winston Churchill, members of various royal families, three Nobel Prize winners and 20 Victoria Cross holders.