The cathedral’s works of art make very numerous references to the sea. The artisans were instructed to create works that honored the trades of the fishing industry, which is very important in the region. But references to the sea, such as fishes and boats, have been important christian symbols since the Antiquity. The ship and the anchor are symbols of safety.
Interesting fact: Since the 4th century, the central aisle of most churches has been referred to as the "nave". This word means "ship" and its Latin root ("navis") can still be found in words like "nautical" and "navigation". The idea is that this part of the church is like a vessel where the faithful gather and are taken on a spiritual journey.