When a ship needs maintenance on its hull below the waterline, it is docked in Calliope Dry Dock in the Naval Base at Devonport.  In the dock it sits on large wooden blocks, carefully placed to support the bottom of the ship so that the propellers and other underwater fittings are not damaged.  There technical staff, such as the welder depicted in this scene can undertake the necessary repair work.  When this work was painted HMNZS WELLINGTON, a Leander class frigate, had recently been purchased from Britain and was undergoing an extensive refit.