Tech billionaire Mike Lynch died from drowning following the Bayesian superyacht disaster off Sicily, an inquest has been told.
Lynch, 59, founder of software giant Autonomy, was among seven who perished when the yacht sank in August.
On Friday, Suffolk Coroner's Court opened and adjourned inquests for Lynch and three other British victims: his daughter Hannah, 18, Morgan Stanley International chairman Jonathan Bloomer, 70, and his wife Judy, 71.
Suffolk Police Detective Superintendent Michael Brown said Lynch's provisional cause of death was drowning. The others' causes remain under investigation pending further tests.
The Lynches lived in London, while the Bloomers were from Sevenoaks, Kent.
The ill-fated trip was being held to celebrate Lynch's acquittal in June following a US fraud trial over Autonomy's £8.4bn sale to Hewlett-Packard in 2011.
Seven lives were lost when the luxury vessel went down in Mediterranean waters.
US lawyer Chris Morvillo, his wife Neda, and Canadian-Antiguan chef Recaldo Thomas also died in the disaster.
The inquest heard the British victims died at 5am on August 19 after being "lost at sea". The Bayesian "sank rapidly" between 4.15 and 4.45am about 0.8 nautical miles off Porticello fishing village, for reasons "yet to be ascertained".
The UK's Marine Accident Investigation Branch has launched a probe, while Italian authorities opened a criminal investigation.
Suffolk's senior coroner Nigel Parsley adjourned the inquest until April 15.
It comes after a photo was released appearing to show a large door of the Bayesian was closed minutes before the superyacht sank - contrary to claims it may have been left open.
It has been alleged that crew on board Bayesian left a large door towards the rear of the craft’s port side open, meaning waves were able to wash in, contributing to it sinking quickly.
But a photo taken by a passenger on another nearby yacht - the Sir Robert Baden Powell - just 14 minutes before the sinking appears to show the door was shut
