If you're looking for another way to traverse the island, get your bearings, and find out some secret puzzles not accesible from land - why not try a boat? Head to the town area past the Entry Area, and follow the water's edge as you head around the mountain until you come to an empty dock. Solve the simple boat shaped-puzzle, and a boat will appear from the depths - complete with a rough map of the area.
To pilot the boat, start from your current position (the big dot) and draw a path to any of the other ports in the island, and the boat will begin its journey. You can re-route your course at any time, and even stop the boat by tapping the circle to reset the puzzle-map.
The Witness Boat and Map
The map and boat can be first found together in the Jungle area of the island. In the southern part of this area is a path pseudo dock made of rocks. Follow the path and you'll find a simple puzzle.
Once you've solved the puzzle, the boat will rise out of the water. There are six docks around the island. They will be marked by this puzzle. Solving the puzzle will summon the boat to you.
The map inside of the boat is what you'll use to navigate the boat around the island. In addition to marking the docks, there are also significant landmarks and Puzzle Types marked on this map.