The man, thought to be a German tourist, had a mask but kept taking it off on board a vaporetto, the canal city's water bus, local media reported on Monday.
He was forcibly removed from the boat after repeatedly refusing to wear his face mask and mocking crew and passengers who asked him to respect the rules.
The man then tried to board again but passengers blocked his path, with one furious man repeatedly pushing him away from from the boat before having to be held back by others.
The boat eventually left the offending passenger behind on the pier.
The incident came after a group of young adults in Rome made fun of police who asked them to wear masks, with those who refused to comply with the rules handed a €400 fine
Around ten fines for refusing to wear a mask have been handed out each day in Italy since they were made mandatory.
Under Italian rules aimed at stopping the spread of the coronavirus, face masks must be worn on public transport and in public indoor spaces at all times. They are also mandatory in busy or crowded outdoor areas between 6pm and 6am. The only exceptions are for children under six or people with a disability that makes it impossible.
The rules on mask-wearing were tightened
in mid-August as the number of new positive cases in Italy began to rise again.
Those rules will apply until at least September 7th, when the government will decide whether to extend them further.