Quote from : Harry Potter and the Half-Blood Prince Book

It's going to be all right, sir," Harry said over and over again, more worried by Dumbledore's silence than he had been by his weakened voice. "We're nearly there ... I can Apparate us both back ... don't worry ..." "I am not worried, Harry," said Dumbledore, his voice a little stronger despite the freezing water. "I am with you.