Leyrann
Deity
Barbarians use quadriremes don't they? Even before the tech is researched I believed. I imagine you'd have to kill one of those.
I'm not sure, I believe it's part galleys and part quadriremes. That said, I barely ever see barbarian ships at all. I mean, in the game right now (where I'm playing on Island Plates and am myself on a relatively small island), I've played over 100 turns on epic game time, which means I'm now at the celestial navigation research, and even though the (one) barbarian camp I saw was coastal, I didn't see them make boats, even though it created a warrior because the scout had spotted my city before I got the camp.