authorities said on Wednesday.
The decision to impose the ban on all ferry trips between Mariehamn on Åland and the Swedish port of Kapellskär, operated by Viking Line, was made on the strength of passenger surveys.
Smokers are still allowed to light up on the ferry’s open-air back deck.
Although Finland is an EU member, Åland is exempt from membership and its economy depends heavily on sales of duty free goods.
Many Baltic ferry companies stop there to allow passengers to stock up on drink and cigarettes.