Regarding Atlantis, no idea but I'd expect more merchant than warship.
Like a building. A valve with a canvas hose either bundled in a basket on the deck or hanging zig-zag on a thing like a tie rack.
On a more general take, I've never understood those big reels to be for fire hoses. More like rubber hoses for UNREP, cables for mooring. They take up a lot of deck space.
The PE reels also have a fundamental problem- they are empty. I usually solve that by replacing the wire axle (not included anyhow) with a short section of styrene rod closer to the diameter of the reel wheels.