My town in the Basque Country is at least 700 years old (officially), and has lived off the sea for most of the time, sending sailors and fishermen around the world.
The specific Basque dialect we speak is full of words and expressions that were or are still used by fishermen although fishing is now a dying industry and it's become a touristic port. We even have dictionaries that record these words and expressions in order to preserve them.
What are some examples in your places? Do the people of the great ports of Antwerp and Hamburg speak a "sea-dialect"?