Paolo Silvestri, grandson of a retired admiral, and Massimo Falchetti, son of a rich shipping magnate, are studying at Leghorn Academy. The two friends both love the sea, but whilst Paolo has the Navy in his blood, Massimo hates military discipline. By chance Massimo meets Doris, a film actress, whom he begins to court. Paolo also gets to know Doris, and although he is engaged to Fioretta, a good and honest girl, he too falls in love with the film star. However, she advises him to return to Leghorn where he boards the Vespucci for the family's annual cruise. Massimo leaves his college course and decides to abandon any military career. Banished by his father, he obtains a job as cabin boy on a Spanish cargo ship. During the cruise on the Vespucci the crew stop off at the port of Algiers where Massimo's vessel is also docked. Paolo goes to look for his friend, but poor Massimo, having discovered that the Spanish crew are smugglers, has been clapped in irons.