The highest observation point located on-board HMS Hood, was her spotting top:
It is here, that her look outs would have scowled the seas, looking for the tell tale glimpse, of an enemy vessel (in a time before radar). The tripod mast on the back, is where Hood's wireless rig was attached (the six horizontal lines coming in from the top left). Both structures, were supported by a single starfish - the black metallic structure, that's located underneath. One of HMS Hood's three survivors (from when she was sunk), was actually stationed in the spotting top - surviving because he was washed through a window, as everything else around him sunk!