A man is fighting for his life in hospital after being seriously injured by a boat propeller south of Perth on Saturday.
The 27-year-old Singleton man was out boating with friends on the Ravenswood River around 2pm when the incident occurred.
Peel Water Police, Pinjarra Police, Mandurah Detectives and St John Ambulance attended the scene and the man was rushed to Royal Perth Hospital.
"An investigation into how the man received his injuries is ongoing" a police spokesman said.
"The 7.92 metre Cabin Cruiser has been seized for forensic examination."
Anyone with information is asked to call Crime Stoppers on 1800 333 000.Â