Subsequent searches of four other addresses in Bournemouth resulted in more seizures of cocaine, cash, phones, notebooks and other drug paraphernalia.
A Citroen car found by police was also found to have a hidden compartment underneath the rear seats.
Det Con Danielle Hill of SWROCU said: “This OCG were handling substantial volumes of cash and preparing vast amounts of cocaine worth hundreds of thousands of pounds and delivering it to a network of buyers.
“We remain committed to targeting criminals involved in serious and organised crime.”
Prosecutor James Foster from the CPS said it was the “compelling evidence of a large-scale operation” that led to “guilty pleas from all”.
“Their attempts to disguise their activities did not prevent them from being caught, and the substantial prison sentences passed today reflect the seriousness of this offending and the scale of the criminal enterprise involved.”
SWROCU’s investigation was supported by Hampshire and Isle of Wight Constabulary, the Metropolitan Police, Cumbria Police and Dorset Police.
The Dorset force’s director of intelligence, Det Supt Emma Sweetzer, thanked all those involved for their work “in taking these illegal and dangerous substances off the streets and protecting Dorset’s communities from the harm they can cause.”