A swimmer bled to death in a boating accident, having caught his leg on the vessel's propeller, the BBC understands.
An inquest heard Simon Houlder suffered a serious cut to his leg in the River Bure in Norfolk and died the day before his 30th birthday.
His cause of death on 15 September was a haemorrhage caused by severe blood loss, the hearing was told.
It was opened and adjourned for a full inquest on 16 December.
The RNLI crew had told the BBC Mr Houlder's leg was thought to have caught the propeller of the vessel.
The 29-year-old, from Selby in North Yorkshire, was airlifted to hospital by the Coastguard helicopter and later died at Addenbrooke's Hospital in Cambridge.