Look. It's really clear. In the New Testament, Peter is a fisherman, and in those days they sailed by day, but by night, they navigated by the stars.

The stars they navigated by was the fixed star to the north, and about it a well known constellation, Ursa Major, the Great Bear.

But,

By the same constellation is its lesser known name; Saint Peter's Barque

Navigating by the stars is a euphimism of putting ones faith in the heavens to travel back home.

This Pope shall face the most serious crisis to befall the Catholic Church, and many of its flock will look upon the Pope to lead them out, or guide them like the fisherman who guides the vessel by the stars.