When a whale attacked a man in a tinny in waters close to the Queensland–New South Wales boundary, the man sustained severe injuries.

Just before nine in the morning on Sunday, jetski riders off the coast of Coolangatta alerted emergency services after a whale allegedly struck one of the men in their boat.

According to Queensland police, the man in his 40s was unaware of the whale's presence until it materialised in front of him.

He was knocked unconscious when he was struck by the whale’s tail, police say.

“[We] urge all boaties to always wear life jackets,” a spokesperson from Queensland police said.

“Fortunately this man remained in his boat.”

The man was brought to shore by paramedics and taken to Gold Coast University hospital where he was treated for facial and spinal injuries.

Queensland Ambulance Service said he was in a stable condition.