Ralph clings to the notion that his father, who just so happens to be in the Royal Navy, will find and rescue them.  Early on in the novel, he comforts the younger boys by telling them that the "Queen has a big room full of maps and all the islands in the world are drawn there.  So the Queen's got a picture of this island" (17).  Ralph encourages the building of a signal fire on the mountain to aid in their eventual rescue.  Ironically, it is not Ralph's signal fire, but rather Jack's vicious fire he creates to smoke out Ralph during his 'hunt' for the other boy that catches the attention of a "trim cruiser" (202).  The British ship sees the smoke--because Jack has succeeded in torching pretty much the entire island--and the boys are rescued by a British naval officer.