Coroner Barb McLintock said the crash took place earlier Tuesday near Campbell River, B.C. which is located on Vancouver Island's east coast and is 257 kilometres north of Victoria.
"It had only one person aboard," said Coroner Barb McLintock of the plane.
"That person was confirmed deceased after the crash. We got some invaluable assistance from the RCMP under water recovery team and my understanding is the recovery has now been completed."
McLintock said the investigation into the crash can now begin.
No information has yet been released on the plane, the victim's age, gender or hometown.
But a spokesman for the Joint Rescue Co-ordination Centre in Victoria said the crash took place off the west side of Stuart Island, which is located in the Strait of Georgia, northeast of Campbell River, B.C.
He said nobody reported hearing or seeing the crash, and the plane was found upside down by someone who came across the scene.
Rescue crews from the Canadian Armed Forces and Canadian Coast Guard also attended the scene, he added.