Passengers’ injuries after the accident at Horizontal Falls in the state’s north, ranged from head cuts to broken bones, Royal Perth Hospital surgeons said.
A 49-year old woman was taken to Broome Hospital with spinal injuries but was later airlifted to Jandakot Airport in Perth.
Horizontal Falls is an iconic tourist destination where a fast-moving tidal current squeezes through two narrow gorges of the McLarty Range at Talbot Bay.
Twenty-six tourists and two crew members were on board the vessel during the incident at 7am on Friday.
Regional police commander Brad Sorrell said several people were thrown overboard and left injured.
Hospital staff were put on standby from Friday morning and kept busy with multiple surgeries and psychological treatment for patients aged 46 to 70.
Three patients have now been discharged and doctors expect all those involved to make full recoveries.
The investigation into what went wrong is ongoing.
The company involved insists its vessel didn’t capsize, rejecting police and witness claims passengers were thrown into the water.