AI still cannot brake off naval blockades efficiently

[Mik1984]

I was blocking a coastal 19 capital city a privateer with combat I+II upgrades. In the city, there were 13 caravels and 4 galleons. No frigates, the civ didn't even have gunpowder = a long shot away from chemistry.
Of course none of those ships would stand a chance in a single engagement, but it is more than likely they could get rid of the privateer with sacrifice of 2 or 3 caravels. No, they allowed him to blockade the city for hundreds of turns.