This was a particularly enjoyable part of the game. As I walked or sailed around the island there was always an objective within sight to try and reach, such as treasure chests, items to pick up or new paths or objects to interact with (such as a jumping pad hidden behind the island).
Out at sea things got more interesting as entirely new paths could be found such as from seemingly insignificant islets, which would lead you to new objects, items, treasure and paths back on land.
Sailing around on the boat was also quite a joy...though with the number of ways (harpoon, storage, garden, salvage claw etc) you can use the boat combined with the puzzle like nature of the maps means that mastering its use will definitely be in your favour.
There are also plenty of non combat related zones, such as NPCs, Stalls, building and towns to explore, which also have hidden goodies to be found..