Police have seized 42 grams of cannabis from three fishing boats off the West Australian coast following the start of the fishing season in Carnarvon.

Officer-in-charge Detective Sergeant Jeramy Davies said police were cracking down on illegal drugs in the area as the season's start brought more people into the north-west town.

"During the fishing season there tends to be an increase in antisocial behaviour by not all, but some people on the boats," he said.

"We want to start of the season by putting the message out there that we won't tolerate this behaviour and we'll come looking for you where ever you are."

As part of the investigation, with help from the Department of Fisheries, police travelled up to 40 nautical miles off the Carnarvon coast on May 14 and boarded five fishing vessels.

Detective Sergeant Davies said the cannabis was found stashed on the boats.

"A person under the influence of illicit drugs isn't just a danger to themselves, they are a danger to their workmates and they are a danger to the community they work in," he said.

"Policing is about being anywhere, anytime, and this new approach should send a clear message to anyone considering taking illicit drugs to regional WA that they are not outside our reach."

A 38-year-old Denham man, a 50-year-old Cape Burney man and a 26-year-old Rangeway man will appear in court at a later date on the offence of possessing a prohibited drug.