HMS Hood was an Empire Ship that sailed the world. As such, her upper decks were an interesting mix, of both peacetime and wartime:
For me, the peacetime is represented by the variety of smaller boats that she carried on-board. I believe that these were used when she was in port, or when she had anchored off some tropical island, for some rest and relaxation (for her sailors). Yet, she was still a warship, with the armament to match! Here we can see: a 5.5 inch naval gun (lower left), a 4 inch high angle anti-aircraft gun (middle-bottom), and a quadruple 0.5 inch anti-aircraft gun (middle-bottom right). Now, I've heard it said, that sailors don't have a fear of heights! Hood's main mast, would appear to test this theory - with the mast's ladders being used to gain access, to both lookout posts, and wireless radio equipment. The long horizontal boom, that stems from the base of the main mast, is the main derrick, which was 65 feet long! I believe this was used, to lift both the smaller boats, and other heavy equipment (such as ammunition crates).