Originally posted by AugustusKron:

the boat is definitely a great upgrade, and you're going to need it anyway. sail at night and into leechy waters without being afraid of losing it. really helps when you're trying to extend your range and go after the elder or look for good swamps

the only thing longboat gives you over carve is storage slots. but you don't need storage unless you're transporting large amounts of metal (which for only reaching iron age sounds quite unreallistic)