The Stranger From The Sea by Rene Guillot .
Mario is a poor Fisherman's son in Genoa. The old boat with which he earns a few lire ferrying market women sinks in the port. The man who helps him salvage the boat is the "stranger" a foreign seaman who is acting as a night watchman while his injured leg recovers. The "stranger" gives Mario a beautifully made model boat in a bottle, intending him to sell it to raise some money, but the boy throws it into the sea, with a message inside it:
"I would like to have a boat, a real one, with a polished mast, a mainsail, and a jib. Thank you."
His message is answered by a wealthy painter and Mario is ecstatic. But his happiness is shortlived, for a number of disasters follow and the boat has to be sold, Mario's friend the "stranger" finally leaves the boy, but by this time he has learnt to face the future with courage.
 Translated by Gwen Marsh with illustrations by Jacques Poirier.