In The Cay by Theodore Taylor, Timothy did many things for young Philip. First of all, he saved Philip's life. As Philip and his mother were getting into a lifeboat after their ship was torpedoed, Philip was hit in the head and knocked out. Timothy, who worked on the ship, grabbed him and put him in a raft. Once the two of them get to the cay, Timothy helped the now blind Philip over and over. He built a hut for them, he fashioned a vine rope, so that Philip could get around the island. Timothy taught him about the island including how to fish, catch langosta, and where to find fresh water to drink.
During their time on the cay, Timothy prepares Philip for just about anything that might possibly happen including bad storms, so that Philip will be able to survive should something happen to Timothy, which of course, does.