The Wind Waker
The Sea Chart shows Link a map of the particular square on the map he is in. Link can update his Sea Chart with information obtained from the Fishman by giving him All-Purpose Bait, and in return, he will help Link add the map of the current location Link is in. When Link has an assignment to travel to a specific location, the island where he then travels to is surrounded with a blue symbol, and is the location Link must travel to in order to move on with his adventure. If Link tries to sail out of the map, the King of Red Lions will turn back. The small red spots that appear in various positions on the map show up whenever Link has acquired a treasure there.
Link gets the Sea Charts from the Temple of the Ocean King. Link needs these to get to other parts of the ocean to fight temples and follow the Ghost Ship to find Tetra. They are also used to find other islands named and unknown.