One man was arrested and taken back to Kerikeri Police Station. Two others abandoned their boat and fled on foot. Police were still looking for them late yesterday.
Both boats were seized - one a 6m aluminium tinny, the other 4m and made of fibreglass - as well as outboards, fishing gear and enough oysters to fill a police trailer.
In an extra twist, the tow truck transporting the boats to a secure Fisheries yard in Whangarei was given a police escort after a vehicle reportedly tried to run it off the road just south of Kawakawa about 4pm yesterday.
Police are investigating whether the offending driver is linked to the seized boats.
Oyster farmer Alan Brain said thefts had been occurring as long as he'd been in the business - 46 years - and he'd had "an absolute gutsful".
The raiders knew it was theft but he suspected they didn't know police had the right to take their boats. The oysters recovered yesterday were worth up to $8000.
Mr Brain said he lost thousands of dollars worth of shellfish a year and often resorted to sleeping on his boat. Growing an oyster took four years, a major investment of time and effort.
"So for someone else to come and reap the rewards of that effort, it's devastating."
Other businesses could put up gates or pay for security guards but that wasn't an option for oyster farmers, he said.
Senior Sergeant Chris McLellan, of Kerikeri police, said a 41-year-old Te Tii man would be charged with theft. The boats had been seized because they had been used to carry out an offence.
Farmers were reasonable people but they were frustrated by ongoing thefts, he said. It was a loss to the country as well as to individual farmers because the stolen shellfish could not be exported.
Anyone could take the wild oysters that could be found in Te Puna Inlet or elsewhere around Northland, to a limit of 250 per person per day, but taking shellfish from a operational farm was theft.
"The bottom line is, there's enough for everyone, as long as no one gets greedy."
Bay of Islands police were looking at using cameras and patrols to target people stealing shellfish or breaching bag limits this summer.
The Ministry of Fisheries is also considering prosecuting the man under the Fisheries or Animal Products acts.
Meanwhile, Mr McLellan said police were following "positive lines of inquiry" as they investigated the theft of 200kg of scotch fillet steak and a large quantity of salami from Churchills Fine Meats in Kerikeri this week.
The salami was uncured and not safe to eat. The stolen meat was reportedly worth $16,000.