The Galley is the first naval unit available in the game. As could be expected, its combat capabilities are quite limited, but it is relatively cheap to produce and can still be used to explore and conquer coastal cities, or harass the enemy by pillaging coastal improvements.
Combat using a Galley can be extremely unpredictable. Due to their weak nature, most fights they enter will likely result in either a stalemate or their defeat. Beware of land-based ranged units while exploring with the Galley!
With a shallow draft, slender hull, minimal decking, and propelled by oars, the galley was the first boat (or ship, if grandiose) dedicated to warfare. Although most had sails on a single mast that could help, galleys were propelled primarily by human sweat. Galleys tended to stay in shallower waters near shore, not being particularly seaworthy. But these were the mainstay of the early Phoenician, Greek, Carthaginian and Roman navies in the Mediterranean … as well as barbarian pirates everywhere. Initially carrying just archers and spearmen for floating melee battles, eventually rams, catapults and even cannon were added to their armaments, making them useful even into the early Medieval Era. But in time the galley – and all its descendants, the biremes, triremes, dromons, etc. – were made obsolete by the more maneuverable (and bigger) sailing warships. And those didn’t need a bunch of sweaty and grumbling oarsmen.