>>1915200ADV motorcycle. ATVs need to be taken anywhere you want to use them (unless you've got a bunch of land). Boats can at least be kept on the water.
if strictly choosing between the two I'd go with boat. you don't really think of an ATV as a vehicle you take and stop off to camp or do something... you just ATV for fun or for utility. boats are cool cuz you're stopping for fishing, you can cook on it, stop off at islands, take friends or family, ect.
