The boat of two fishermen missing from Port Waikato since Monday may never be recovered, police say.
A police helicopter was scouring Port Waikato again today in search of the men.
Arthur Brown, 67, of Tuakau and his 57-year-old friend from Pahiatua in the Manawatu were reported missing on Monday night after failing to return from a fishing trip.
Their boat was located at the river mouth, 3kms from the Sunset Beach Surf Lifesaving club.
Tuakau police Sergeant Tod Kirker said the boat might end up being buried under sand.
"It's sitting on a sandbar island about 1km in circumference," he said. "It's under water and in high tide. It's been sucked in to the sand in quite a dangerous bit of water."
Coastguard hadn't been able to get another vessel within 200 metres of the boat, he said.
"The difficulty is you can't get a vessel near it because of the depth of the water. Coastguard were able to clear the boat and confirm that no one's inside but their attempts to upturn it were unsuccessful.
"There's a possibility that in a different tide and bad weather the boat may come a float but the other possibility is it might get further sucked under the sand."
Coastguard's NZ Steel Rescue vessel, the police Eagle helicopter and the Westpac Rescue Helicopter, as well as two local surf lifesaving clubs have been involved in the search for the men, who were believed to have been trying to cross the Port Waikato Bar.