Water Police and 40 State Emergency Service volunteers from DFES have on Saturday joined the police search for 66-year-old man Peter Henry Woods.
They will focus on both sides of Serpentine River in Coodanup, where the missing man lives, after an overnight operation that involved local police, DFES volunteers, Water Police, the Canine Section and the Police Air Wing .
Police hold welfare concerns for Mr Woods, who has not been seen or contacted his family since leaving his home, about 70km south of Perth, at approximately 9.30pm on Monday April 27.
Police described the missing man as dark skinned, with a medium build and approximately 178cm tall.
He has greying hair and brown eyes and was last seen wearing a large black jumper, dark blue tracksuit pants and no footwear. His family and police have concerns for his welfare.
Anyone who sees Mr Woods or has information on his whereabouts should call police immediately on 131 444.