Police have set up a mobile truck at Waiwera and are asking for information from the public as the search for missing former league coach Mike McClennan enters its fourth day.
An officer at the site said dozens of members of the public had stopped to volunteer to help.
Searchers were scattered up and down the highway, and there were police cars at Waiwera, Hatfield's Beach and on the hill overlooking Orewa.
The search area includes beachfront, cliffs and tracks through steep bush.
McClennan, 75, a former international league coach and Kiwi league fullback, was last seen walking Northbound on the Hibiscus Coast Highway about 5pm on Wednesday.
He had left his residence, the Milton Court Rest Home, on Milton Rd, Orewa.
McClennan is the father of former Kiwis and Warriors coach Brian "Bluey" McClennan.
McClennan is about 1.7m tall, with grey hair and was last wearing a red and black St Helens league tracksuit top with blue jeans. He is also wearing a bracelet with his wife's contact details, his son says.
"He's a really approachable, kind man but he'll be confused."
Police are also appealing for any motorists with dash camera footage, who travelled between Silverdale and Warkworth yesterday between 3pm and 10pm, to check their footage for anyone matching his description.
"We are particularly interested in speaking to anyone who travelled on the Hibiscus Coast Highway during those times who may also have dash camera footage," a police spokesperson said.
Police believe it's possible he may have been given a lift by a member of the public in their vehicle. Anyone who saw or picked him up is asked to call 111.
There had been unconfirmed sightings of McClennan heading north on the Hibiscus Coast Highway toward Hatfields Beach, around 5pm. The family were surprised by the reports as they believed McClennan would have headed for Grey Lynn or Mt Albert.
"Whenever you talk to him he always thinks he lives in Maidstone St again, where he grew up. It's off Karangahape Rd, right in the heart of the city," Brian said.
"Or he wants to get to Fowlds Park in Mt Albert. He used to coach there ... his mind always takes him back there.
"Honestly, there are so many people scouring the area, it's pretty humbling. He's a pretty popular, well-loved man."