A group of young relatives embark on a holiday voyage that becomes a perilous series of maritime misadventures after their craft is wrecked. Stranded at sea and ashore, they struggle with storms, isolation, scarcity of food, and repeated attempts to escape and be rescued. Their ordeal leads to island exploration where they confront wild animals, treacherous terrain, and hostile humans while pursuing clues to a long-hidden pirate treasure. The narrative follows their planning, narrow escapes, confrontations over the loot, and a final revelation about the contents of a mysterious box that concludes the hunt.