Grave concerns for missing Waikiki fisherman

The search for a missing Waikiki fisherman north of Perth has now entered its fourth day.

Despite a massive search effort at Green Head, there has been no trace of Ian Gray or his vessel.

The 46-year-old's car and trailer remain at the boat ramp.

The alarm was raised after Mr Gray, an experienced fisherman, failed to return from a fishing trip on Sunday afternoon.

Police say he knows the area well.

On Tuesday, the sea search was extended down the coast from north of Leeman and south to Grey.

SES volunteers have also been patrolling areas between Cervantes to Jurien Bay and Sandy Cape to Green Head, while police horses are searching the coastline.

Police air-wing and drones will continue the search above on Wednesday.

Police Commissioner Col Blanch said they are still hoping to find Mr Gray alive.

“We will keep going. We do get advice from specialists about expectations and how long people can survive in the water, but we’re not giving up hope yet,” he said on Tuesday.

“We’re out there everyday. We’ve got aircrafts, we’ve got boats, we’ve got land searches, and marine searches.

“We will keep looking and hopefully we find him soon.”