BC Ferries spokeswoman Deborah Marshall says the accident took place early Thursday evening at the head of a ramp on Mayne Island, which is located between the Lower Mainland and Vancouver Island.
She says the vehicle did not go into the water but ended upside down on a rock barrier formation known as rip-rap.
Marshall says a doctor was in the ferry lineup at the time and offered assistance.
BC Ambulance Service spokeswoman Chris Harbord says local paramedics responded to the accident and an air ambulance from Vancouver transported the driver to Victoria General Hospital.
Marshall says the RCMP is investigating the matter, BC Ferries will conduct its own internal investigation, and one of the island's two ferry berths will remain closed until workers can repair the wooden barrier.