Here's a rough map of the first floor of the vessel, should you all wish to enter (it's up to you!)

Here is what Aredhel may glean from Carus's investigation:
1: The entrance. broken into the hull of the ship is a way in - several sturdy planks ramp upwards to allow entrance.
2: Six hammocks are on this side of the ship, one high and one low on each section.
3: The main mast pole for the ship.
4: Three were-rats sit here on rickety chairs. They look like flea-ridden, underfed wretches. they are playing some kind of gambling game with knuckle-bones on the table and arguing amongst one another about how hungry they are.
5: A hessian sack sits here, next to the rats.
6: A seperated room without a door. Contains two chests, one broken.
7: Stairs up to the deck.
Several torches are in holders along the walls. The place is filthy with faeces and general waste, and smells horribly (think dead mouse/rat smell.)
I'll draw up the 2nd floor at a later date.
Also a disclaimer: don't pay TOO much attention to the Pathfinder's were-rats as according to the book or website; I'm trying to equalize things for the game and it may not match up to what the pathfinder book says. This goes for all enemies, past and future.