"We have a dark scary forest (danger), a bright "shimmering" lagoon (excitement), and a wide open sea (isolation)."
-Analysis of Shmoop University-
The place where the story occurs is a huge island which has only some pigs, and forests near the Pacific Ocean because the author mentions "Pacific tide". So it might be somewhere close to Japan, Philippines, and the United States. Boys have a bathing pool that they can take a shower near their shelters, and the beach where they can play around during free time. And the period of time is during the World War II, an atomic war.