Message in a Bottle (Falcon)

A girl put a message in a bottle and threw it into the sea. They give hints about the story of the Falcon Bastion.

The bottle west of Gray Beach has this message:

You find a letter inside the bottle. It says: 'I'm locked in a tower atop a fortress to the south of a foreign continent, help!

The other bottle seems to be unreachable and thus the message in it cannot be read.