Ten current meter moorings, a weather station, two tide gauges and 45 temperature loggers were deployed at Scott Reef, prior to the coral spawning event in March, 2003 and recovered in June, 2003. In addition to moored instruments, surface drifters were deployed to map surface circulation. CTD casts were also made. Arrays of instruments were deployed to quantify patterns of water circulation and stratification in the vicinity of Scott Reef. Surface drifters were deployed to observe both the local fine scale circulation in the immediate vicinity of Scott Reef, and to better understand the potential connectivity between reef systems along this region of the West Australian North West Shelf and possible transport of spawned material. The goal was to elucidate key physical oceanographic mechanisms influencing observed temporal and spatial variability of coral recruitment and coral bleaching at Scott Reef.As part of this study a preliminary depth-averaged hydrodynamic model was developed and applied to describe in broad detail the major features of depth averaged tidal circulation. This research is the "Physical Environment" sub-project of the project "Biological and Physical Environment at Scott Reef 2003"