When Robinson awoke the next day, the storm was gone. He saw his old ship stranded about a mile out at sea. Along the shore, he saw the wrecked remains of the boat he and the other sailors had tried to escape in. When the tide went out, Robinson was able to walk out until the ship was only a quarter-mile from him, so he swam to the ship and climbed aboard, hoping to find some supplies.
He doesn't recognize it as such now, but Robinson will later appreciate how fortunate he was that the ship was stranded so close to shore, an example of God's good will and providence.
On the ship, Robinson found some food and other supplies. There were no small boats, though, so he had to construct a raft from some scrap pieces of the ship's wood. He loaded the raft with food, liquor, guns, ammunition, and some tools. Using some broken oars, Robinson was able to guide the raft toward the land and into the mouth of a river.
By himself, Robinson cleverly salvages some scraps of wood into a raft, exemplifying the kind of resourcefulness that a life of isolation requires.
Robinson's raft was unstable and he almost lost all of his provisions into the water several times, but he was able to guide the raft along the river and find a place to put the raft on the bank and get all of his supplies onto dry land. Robinson then climbed to the top of a nearby hill to survey where he was: he found that he was on an uninhabited island.
Robinson now realizes that he is indeed all alone on this island. He is isolated in every way imaginable from society.
On the way back to his cargo, Robinson shot a bird and says that this was the first time a gun had ever been fired on this island. He made "a kind of hut" with some barrels and chests and planned to make another expedition to the ship.
Completely separated from society, the island had never before heard the shot of a gun—though it's interesting that the sign of civilization is the sound of the firing of a weapon. Robinson begins to make a dwelling, the first step in establishing a life on the island.
Robinson went to the ship many more times, bringing back more food, tools, guns, and various scrap parts of the ship. One time, he found some money on the ship and laughed at how useless it was. He used the ship's sail to make a tent and fortified it all the way around with boxes and barrels to protect him from any wild animals. One day, a powerful storm blew the remains of Robinson's old ship away.
Already isolated on the island, Robinson surrounds his dwelling with a fortification, cordoning himself off even more as an individual. Robinson realizes that outside of society, in a state of nature, money is completely worthless.
Robinson saw a raised plateau against a rock face and decided to move his tent there so that he could see if any ships came by at sea. Using parts of the wrecked ship, he built a protective fence around it, though he says he now knows there was no reason for such caution.
With hindsight, Robinson realizes he didn't need his fence. The fence can be seen as symbolizing his isolation, as he is figuratively fenced off from the rest of the world on the island.