The OILTRANS oil spill modelling component provides an integrated oils database, three-dimensional hydrodynamic, meteorological and particle transport mathematical model that estimates the volume of oil remaining on the water surface, evaporated from the water surface, dispersed into the water column, emulsified into highly viscous oil, or washed ashore. The OILTRANS modelling system was developed to provide a user-friendly link between the OILTRANS oil spill modelling computer code and a GIS, the latter providing facilities to create parameter files for OILTRANS simulations and the visualisation of simulation results. The system operates within the ArcView GIS developed by ERSI Inc of Redlands California and was developed through the ArcView 9.x programming language of VBA. This document is to be read in conjunction with previous ARCOPOL report: “Development of OILTRANS model code”.