[At the words "Well, yes" Namur's satisfied that that's his final answer, turns, and almost silently slips underwater. He swims down to the door, then straight up so the humans will know where to swim to, so they can have as much opportunity for air before going under.]

Door's straight down, an' there's a staircase headin' down t' starboard. Get yer breath here but come down quick. I'mma swim ahead an' get started on the shitty rubble.

[And after slapping his position on the wall with a wet hand, he dives again.]