Instruments sampling the engine cooling water on two B.C. ferries were used to monitor the temporal and spatial variations of the Fraser River Plume, in the central Strait of Georgia (British Columbia, Canada) for nearly two years. Travelling along two different routes north and south of the river mouth, each ferry provided eight horizontal near-surface salinity transects per day. From each transect, the arithmetic average salinity along the section (denoted southern or northern section average salinity) was extracted, formulated as a time series of hourly or daily values and then compared to equivalent computer simulated series.A numerical model, previously developed to examine the effect of tidal forcing on the plume, was modified to include as inputs the hourly wind and daily discharge data. Average model salinities along the ferry section were computed and compared to the observed ferry data. Good agreement was reached after manipulating the entrainment velocity and the momentum transfer from the wind to the plume. The tides were seen to add a relatively small tidal modulation to the general salinity pattern resulting from the combined effects of wind and discharge.