Assassin's Creed IV: Black Flag Part 100
Devils of the Caribbean: Brothers in Arms
Note: Fighting one tough ship is hard enough, but two makes it extra tough. No lie, took me an hour to figure out how to deal with the two together. When one ship goes down, the other gets a huge boost in firepower....and the ship itself sets on fire and can ram you for serious damage, if not outright sink you!
The way I tried it is to weaken the two so that their health is low enough to take down almost simultaneously....it won't be easy though, as it is a 2-on-1 battle.