A 72-year-old Dudley Park man died after a vessel capsized near Boundary Island this morning.
Police were notified of an emergency situation to the south of the island in the Peel Harvey Estuary at 10.30am.
The information received was that the skipper of a vessel was seriously injured and had been taken on board another vessel.
A marine search and rescue operation was initiated with the Mandurah Water Rescue Group and Peel Water Police vessels deployed to respond to the emergency.
The vessel with the injured man was located and he was transferred to the Mandurah Water Rescue Group vessel and was taken to shore to an awaiting ambulance. Attempts to revive the man were unsuccessful and he passed away.
An investigation into the incident will be conducted and a report will be prepared for the coroner.