The maps are huge, and you can finish the current game exploring 5% of it or so. Im on the last boss and have explored 2 islands partly.

You can explore it however you like, but
- boating, while risky at times, is faster (straight line between points, and high speed with wind or skill) and it lets you see what is there from a safer location if you stay just so far from the shore, enough to see what kind of zone it is from relative safety. Note that the raft is just not safe, use the karve to do any real boating.
- portals help go back home to dump loot and get rested again and avoid nightfall.
- one zone of a type is like any other with some exceptions; some zone are not big enough or something enough to have what you need (eg, some mountains are too low to have metal, the main reason to visit). Its hard to tell that without taking a quick look around, though.

Some games are not meant to explore every inch of the world. This is one of them. Its pointless, since one meadow is much like another, and there isnt time (it would indeed take potentially a year + to touch all of a map). That is ok. Enjoy the world your way, at your pace. And, there are near infinite worlds if you don't like yours.