To get this you need to make it to the island. To do that you need to grab the boat looking item from the tree north of the starting house and take it to the man on the beach by the lighthouse.
Once you give it to him you need to die and run back and he will tell you to jump in. Then you need to activate the terminals on the island and go through the first teleporter. To open up the rest you just need to use the teleporters in the Hotel, the Sneaker store and the Island hut.
You can find me going to the island at 24:00 in the video below