A short-circuit caused the fire which destroyed a private yacht and extensively damaged a second one in Latsi on February 4.
The vessels were docked side by side when the fire broke out in one of the two in the morning.
The blaze erupted while its owner and technicians were onboard doing maintenance work.
Some €15,000 in cash which the owner had on the boat because he was going to pay the technicians also went up in flames.
Workers said they noticed smoke coming from the vicinity of the propeller and immediately disconnected the battery.
The fire spread quickly because of flammable materials kept on board, despite the efforts of the owner and the workers.
It was eventually put out by the fire service which, along with the ports authority, also took measures to prevent pollution of the sea.
The vessel was insured for €70,000.
The cause of the fire was determined after examinations were carried out by the fire services, the electromechanical services and the port authority.