Large-scale cannabis growing operations - including a yacht and makeshift growing rooms in shipping containers - have been busted by Auckland police today.
At one address, more than 100 customers were coming to buy the drugs each day.
An early-morning search by 46 officers across ten addresses in Beach Haven, Sunnyvale, Henderson, Massey, Albany and central Auckland found more than 1000 plants worth thousands of dollars.
A yacht moored at the Westhaven Marina was also searched.
In a statement, police said there were 800 cannabis plants, of which 600 were mature, were at one address alone - an industrial unit in View Road, Henderson.
Described as a "well-established commercial growing operation" several rooms inside the unit were dedicated to the growing process, including a nursery where plants were cloned and a commercial shredder to destroy the plant stalks.
"Two shipping containers have been moved into the unit, and transformed into growing rooms, complete with ventilation systems and charcoal filters to keep the air clean," said the statement.
"When officers removed the lids of two fish bins, they found thousands of dollars' worth of cannabis head."
The scene is under armed guard and a number of specialised police, including forensics, were still on the scene.
An ESR expert with specialist knowledge of commercial cannabis operations has flown up from Wellington and will work towards placing a total dollar value on the amount of cannabis found this morning, including past income and potential proceeds from the criminal activity.
Detective Senior Sergeant Stan Brown said: "The electrical setup here is extremely professional and has been very cleverly done, to the extent that the wiring has been done so that the majority of the power isn't being paid for.
"The offenders here have invested a substantial amount of money into this operation."
In Beach Haven on Auckland's North Shore a further 246 plants were found growing in the basement of a house.
Police officers also searched a yacht in the Westhaven Marina, a commercial unit in Albany, and residential addresses in Sunnyvale, Massey and central Auckland.
"We know that at one address alone, more than a hundred people a day have been visiting to purchase cannabis," said Mr Brown.
Today's search warrants were the culmination of a months-long police investigation into cannabis operations in the Waitemata Police District.
That covers the area north of Auckland from Devonport to Managawhai, and the entire stretch of motorway between the Bombay Hills and Orewa.
"For some time we've been aware that the growing and sale of cannabis was happening in our district.
"Today's operation will significantly disrupt and stop that."
Eight people were arrested and all are expected to be charged with supplying or cultivating cannabis, said Mr Brown.
More details about the arrested parties will be released later today.
Motorists are being warned to expect hazardous driving conditions.