The Dink Network

Well...idk if you guys know about this (but im sure at least someone does), if you go to the duck town place where you kill all the ducks and they make a dink smallwood statue and go to where the statue is. You can go down one zone, then right one, then down one, then right one, and down one more. Walk to the up and right area to where all you can see is his feet. Walk all the way to the right so you are in the corner. If you hold right so you are walking against the water then start holding up too, you'll zone up and right and be walking on the water. Everything is reversed with walking. Well, if you do that and start at the zone and follow the water path up. You'll eventually get to a spot where you can go straight or right. Go right and you'll end up by some sand bars. Follow the path down. You'll see an island with stairs on the left, a chest on the bottom right, a red potion, and a couple volcano looking things. How do you get there!?! Or is it like...a test type area? I have no clue..