As we understand from the passage, the boy ----.

The wind that day was light and fresh and came from
the west, and with it at noon a little boat came
quickly, over the bright waves, into Sattins Harbour.
While it was still quite a distance away, a sharp-eyed
boy spotted it and, since he knew, just as every child
on the island knew, every sail of the forty boats of the
island fishing fleet, he ran down the street calling out,
“A foreign boat, a foreign boat!” The lonely island
was rarely visited by a foreign boat, so, by the time
the boat had arrived half the village was there to
greet it. Fishermen were following it homewards, and
those who happened to be inland, were climbing up
and down the rocky hills, and hurrying towards the
harbour.