PEEL Water Police officers responded to a vessel overturned near Fathom Bank, west of Mandurah, this morning.
Water Police and Volunteer Marine Rescue were advised of the overturned vessel at about 8am and responded.
It is believed the three men on board were checking crab pots. All passengers were rescued by rescue helicopter and boats.
The passengers were taken to Mandurah to be assessed by St John Ambulance personnel.