Thomas Wainwright was on the wrong side of the road and travelling at speeds of up to 95mph in his Maserati hire car, just minutes before the crash.
The 27-year-old ploughed into the Berlingo van driven by Theresa Wade, 29, on Mull in October 2015.
The court heard Wainwright had been drinking cider and whisky for eight and a half hours before the crash.
He will be sentenced next month.
During the trial Wainwright and his passenger,  42-year-old Jerome Lopez, had claimed that Miss Wade had been on the wrong side of the road and caused the accident but the jury did not believe them.
Witnesses from Mull told how Wainwright, who was with Mr Lopez, his mother's partner, had been drinking at a hotel, a pub and a distillery in Tobermory before having another two pints of cider in the Craignure Inn.
As he headed back towards Tobermory on the wrong side of the road his hire car smashed into the van driven by Miss Wade.
The court heard Wainwright was on Mull, along with members of his family, visiting his sick grandmother. He had flown into Edinburgh airport and hired the Maserati.
Prosecutor Tim Niven-Smith revealed that Wainwright, who worked as the first officer on the Â£6.26m yacht MY Mahogany based in the south of France, had a previous conviction for driving while unfit through drink or drugs.
At a court in Nice he was fined 700 euros and given a suspended sentence.
Judge John Morris remanded Wainwright in custody and banned him from driving.

The base, near Albrighton, is home to the Defence College of Aeronautical Engineering.
Its future was put in doubt after the government announced last year that RAF Lyneham in Wiltshire would open a training college in 2013.
The RAF said working with private firms could help Cosford survive.
Station Commander Jamie Johnston said: "We already have trained some elements of British industry.
"Industry are finding it harder to find trained people and it's expensive to train people. It makes sense to look at how we can do that in a smarter way."
RAF Cosford is estimated to contribute about £70m a year to the local economy.
The government has said the base could be used by soldiers returning from Germany, although that is unlikely to happen until 2020 at the earliest.
Shropshire councillor Malcolm Pate said it made sense to look at different ways to secure the base's future.
Mr Pate said: "Given the technical expertise that's at RAF Cosford, I think there's a great opportunity for Cosford to have a large income stream by selling its expertise to local companies and private business."
The government has revealed that a six-year review into the move of aeronautics training from Cosford to St Athan in south Wales cost taxpayers £150m.
Station Commander Johnston described it as a "large sum of money" and said the military had a duty to deliver best value for money for taxpayers.
Plans to move the training college were scrapped two years ago, news of which was welcomed by local business leaders, councillors and Conservative MP for the Wrekin Mark Pritchard.
A drink-driver who killed an island vet in a head-on collision has been found guilty of death by dangerous driving.
[NEXT_CONCEPT]
RAF Cosford in Shropshire could sell its training expertise to the business community if the government moves its defence operations.