This series comprises diaries of the Harbour Master at Christmas Island from 1950 to 1958. The diaries were a daily record of activities, e.g. ships arriving and departing, maintenance and repairs being carried out, etc. as well as weather observations made by the harbour master.  
The harbour master was James Reginald Smith who must have taken the diaries with him on his departure from the island and then subsequently donated to the Commonwealth by Mr Smith's widow in March 1993.