Swamped

You look around again, and you spot something odd about the wall. There's a small gap between two metal lines.

You get closer, and you think you can see something in the gap. Something... blue?

You hold onto one of the metal lines to lean in for a better look, but then you feel it start to move.

The walls here roll back. There are windows beyond them. This must be for observation.

And it confirms that you are, in fact, in the sky. Clouds flow past outside - with surprising speed. So this place is moving, then?

You pull the metal line back. No sense making it obvious you were here, so it's time to think about your next move.

You don't have any paper ready, so you try your best to think about the distance you've traveled in your head. If this place is about the same size as an oceangoing ship, then the door to the storage room was probably about halfway to the end of it.

In all that time, you've only seen three rooms, but you didn't explore any halls. Still, you glanced at them long enough to get a sense of their size. Which means you have a rough idea of where other rooms could even fit.

Your mental map is far from perfect, but it's better than nothing. So where do you plan to go from here?