The shack is indeed built on poles because of the tides. There is one door on the shack with a ladder leading up to it, and one window on the other side with closed shutters.
The party sneaks below the shack to eavesdrop.
"- utterly bored. There's been no action for days."
"Yeah, it's like Roger is suddenly afraid of those Bonebeards or whazzacallem."
"I don't get it! With the ships and machinery that we've got, we should be ruling the Crystalline Sea by now!"
"Don't sweat it, matey, have a swig of rum instead!"
Then the crowd inside the shack burst into a booming laughter that was cut short by a hushing voice.
"Morons! We're supposed to be keeping guard out here. So stay quiet and gimme that bottle, will ya?"
What will the party do next?