Boarding a slave ship and liberating its human cargo is probably the most satisfying thing you can do in the new Freedom Cry DLC for Assassin's Creed IV. It's also one of the toughest. Take a look at how this naval battle to free slaves almost ended in tears.
The video here shows me taking on three much bigger, faster and better-equipped ships to get at the slave ship that the vessels are protecting. You'll be drawing fire from multiple enemies at once since these fights aren't just facing off against one ship at a time. Complicating matters further is the fact that you've sometimes got to aim around the slave ship, lest you hit it accidentally and kill some of the captives on board. You'll see that I almost died here. But, instead, I—and 80 some-odd others—got to live as free men. It's the best kind of reward.