Instability, poor safety equipment and an unqualified crew led to nine Britons being killed when a pleasure boat capsized in Bahrain, a court has heard.
Escape doors on the lower deck were locked
Fifteen Britons were among the 58 killed when the Al Dana dhow capsized in March last year.
A coroner returned a rarely reached narrative verdict, which simply sets out circumstances surrounding a death.
At the end of an inquest at West London Coroner's Court she said alterations to the wooden vessel had destabilised it.
Earlier the inquest had heard how the Al Dana left the marina at about 8pm local time on 30 March last year and capsized about an hour and 45 minutes later.
It had sailed south, passed under a bridge and was turning back when it capsized.
The coroner, Alison Thompson, cited a report into the disaster which found the boat had been "dramatically altered" with a superstructure built on to the traditional dhow, destabilising it.
Air conditioning units, a kitchen, fridges and a generator had all been added.
She said the 130 people on board to celebrate the end of some work on a major building project had contributed to the boat's instability.
The inquest also heard escape doors on the lower deck were locked and lifebuoys were tied to handrails with nylon ropes.
Jason Brett and Lucinda Lamb were thinking of settling in Bahrain
Solicitor Clive Garner, representing more than 50 survivors or bereaved relatives, said they welcomed the verdict.
"The coroner has concluded that the capsizing of the Al Dana was due to a number of errors by those very people responsible for passenger safety.
"It is now clear that this vessel should never have left the quayside."
There were still questions that needed answering to ensure justice was done for the victims and so lessons can be learned, he said.
The coroner is expected to ask authorities in Bahrain to improve their procedures.
Ms Thompson recorded a narrative verdict for the nine Britons and one German whose bodies were repatriated to the UK.
Patricia Doyle, 64, of Hagley, Worcestershire, and her English language teacher daughter Roslyn, 35, who she was visiting on the Persian Gulf island
Scott Belch, 33, from Redhill, Surrey, and his pregnant German wife, Sandra
Jason Brett, 32, and wife Lucinda Lamb, 30, who moved to Bahrain from Surbiton, south London, and left behind two young children
William Nolan, 50, from Ipswich, Suffolk
Stephen Grady, 42, from Hebden Bridge, West Yorkshire
Carl Ottewell, 40, from Bolton upon Dearne, South Yorkshire
Phillip Moody, 48, a father-of-two from Southampton who is said to have saved his wife Alison and another woman before he died.