As Jean-Louis Étienne explains in the preface, *The Perseverance*, the world’s largest oceanographic sailboat, sets sail for Greenland. Elsa Pény-Etienne, the author, is the expedition director. Her captivating account tells the story of three young students who, during their 4th-grade class visit, decided to stay aboard! Imagine Elliot, the second captain’s, astonishment when he discovers children—Zoé, Charlotte, and Ulysse—hidden in a locker! He wonders how they managed to last three days? The same goes for Jade, the chief mechanic! They’ll have to tell Captain Ysée! Ysée assigns each young person to a crew member so that “the brats do the same chores as the rest of the crew.” Zoé volunteers to go into the shroud cables where a problem has been reported. Zoé, surprising herself with her composure, astonishes everyone with her agility in climbing a mast while the sea is rough! Ulysse helps a researcher take plankton samples with a 20-micron net. He is delighted to have participated in a scientific study! Elliot reports engine overheating. Jade demonstrates her full talent for “talking to machines.” Charlotte is thrilled to work with Jade, who passionately and patiently explains her job as a mechanic. Readers will learn in a very precise manner, using technical terms, about the various tasks performed aboard the ship. Gradually, the young people will find pleasure in successfully participating in life aboard, discovering the understanding and solidarity among crew members, and marveling at the beauty of the marine world. An unexpected event, the discovery of an active beacon, triggers concern. Tension rises on board! Is it an SOS, a warning? For Ulysse, this will be an opportunity to reveal his talent for deciphering the message. Is it an indication of a specific point? Should they go there? What might they discover? This very lively narrative, presented in the form of dialogues, can be read in one sitting. The reading is captivating, introducing young readers to life aboard a ship, a life full of twists and turns!