Group watched in horror as trio were swept to their deaths on Vietnam 'waterslide'

Izzy Squire, left, Christian Sloan, and Beth Anderson near Da Lat in Vietnam hours before they died in 2016. Photo / Supplied

Backpacking British sisters were swept to their deaths on a waterfall "waterslide" in Vietnam as GoPro footage captured their final moments, an inquest has heard.

Beth Anderson, 24, Izzy Squire, 19, and their friend, Christian Sloan, 24, lay on their backs then threw themselves head first down the smooth 20m rockface, wearing helmets and life jackets.

The trio were expected to get out on to dry land as they reached a 2m-deep pool of water but strong currents swept them down river to a dangerous "tier" of waterfall below.

Their bodies were later recovered from the water with fatal injuries, the inquest at Sheffield Coroners Court heard.

The half sisters from Sheffield, South Yorkshire, had met Sloan, from Deal, Kent, a few days earlier. They booked the morning tour, which was graded "easy" and included "swimming and sliding in two natural waterfalls," for February 26, 2016.

The excursion was with an official guide at the Datanla Waterfalls in the Dalat area.

Sloan's friend, James McGlashan, had been due to join them but pulled out after falling ill.

Christopher Dorries, the senior coroner, said the waterfall was not "typically vertical" but at a 45 degree angle.

Harrowing GoPro footage taken by a member of a group that followed them down the waterfall was shown at the inquest.

Two of the victims could be seen being swept along in the current towards the next waterfall.

A girl from the second group screamed: "I can't stop!" before managing to clamber out of the water after a struggle.

Charles Wilson, a forensic pathologist, carried out post-mortem examinations after the victims were repatriated.

Squire, a talented showjumper, had a "large fracture of the skull" and died from "a combination of head injuries and drowning," he said.

Anderson, a contemporary artist who lived with Squire at the family home, drowned, while Sloan, who had previously worked for the Royal Navy, died from "head and neck injuries associated with drowning".

The inquest heard that research suggested more people had since died at the same location.

Guards are now stationed at the top of each waterfall on the route.

The inquest will conclude on March 19.