The British chief engineer of a super yacht died after being electrocuted as he was repairing a fault without isolating the power supply, an inquest has heard.

Dad-of-two Roy Temme, from Southampton, was one of the 17-strong crew of the 62.5m Baton Rouge as it was alongside in Falmouth Harbour, Antigua, when he embarked on the repair of the ventilation damper in an enclosed compartment of the vessel.

An inquest held at Winchester heard that the 47-year-old could only work for 10 minutes at a time in the overpressure duct compartment because of the temperatures ranging between 50C and 55C – which required him to take ventilation breaks.

Coroner Jason Pegg told the hearing that a report by the Marine Accident Investigation Branch (MAIB) found that Mr Temme had not isolated the electricity for the repair and the electric breaker was found to be still in the on position.

He added that no permit had been sought to carry out the electrical repairs on the yacht, which had no guests on board at the time.

Mr Pegg said that Mr Temme was “hot and sweaty” while carrying out the repair and this would have aided the electricity to flow through his body.

The coroner added that Mr Temme was found by the chief officer, who himself received an electric shock from him.

The coroner added: “The evidence would suggest that when Roy embarked on that task which involved the electric circuits on the ship, there was no making safe of the electrical system by Roy or anyone else.”

He said that a post mortem report found that Mr Temme, who had previously served in the Royal Fleet Auxiliary, had suffered cardiac arrest caused by the electric shock which also caused burns to his body.

This then led to hypoxia – oxygen deficiency – which caused Mr Temme’s death.

Recording a conclusion of misadventure, Mr Pegg said that he would not be producing a prevention of future deaths report as the MAIB had stated that “procedures had been reviewed and existing ones have been reinforced”.

A statement read to the inquest from Mr Temme’s widow Natasha said: “He’s an amazing father, amazing husband, always cheerful, great sense of humour.

“Roy was a strong man, family man, sober habits, courteous and always willing to help.”