GLM analyses are used to standardise the CPUE data for Namibian orange roughy in a manner that deals with tows that record zero catch of orange roughy. The possibility of there being a “learning” period of lower CPUE for a new vessel when it enters the fishery is taken into account. Further, to allow for areal expansion of the fishery at each aggregation, sub-aggregations are defined and CPUE trends estimated separately for each. Different methods for combining the results for the various sub-aggregations to provide a single index for an aggregation are considered. The standardised CPUE values for 2004 (i.e. the July 2004 – June 2005 fishing year) are more often below than above those for the previous year.