what to do with message in a bottle

[Anthony]

During the random sea encounters I keep getting the same message in a bottle:
Save me! I'm in the king's prison. The third chamber from the left.
And don't talk to the Shorty brothers. I owe them a thousand coins.

Is this a hint for something?

[UsaraK]

Cleared the game twice, and none of the messages gave me something important. To me they are jokes or text about some random reference.