As his boat fell into the water, he heard a crackling followed by a thunderous crack. Blinded for a moment, he looked back, just as the ship he had just left exploded. Huge pieces of wood fell around him, causing the boat to veer side to side, and he barely managed to stay inside. Then, he heard the thunder directly overhead, and then the entire world went white. He had no idea how long he had been unconscious, but as he opened his eyes, he found himself lying on a rocky beach. The sun was beating down on him, and the ship he somehow remembered sailing for most of his life was nowhere to be seen. Around him was the wreckage of the rowing boat he had used to escape the ship, but he saw no sign of any of the other boats.
He had to assume most of his crew were dead. He hoped they were alive, but judging by his narrow escape, he didn't hold out much hope. He could mourn them once he had made sure he didn't join them. He was stuck on this island for the foreseeable future, so he would need a few things: food, shelter and clean drinking water. He examined the wreckage of the ship, finding that the emergency supplies had mostly been destroyed by the lightning strike. He did find flint and tinder, and with the trees adjoining the beach, he would more than likely have firewood if he could find something to cut them down with. So if there were any animals on the island, he would be able to cook them, assuming he could even hunt them without weaponry. The trees would also provide some shelter from the elements, but he would need to figure out something more secure in the future.
This left clean drinking water, which would require him to search the island. Standing, he moved into the woods.