The River Clyde is one of the major industrial rivers of Scotland and the shipbuilding on the banks of its estuary has been famous for centuries. With the increase in the size of the ships being constructed and using the Clyde as a port, steps must be taken to ensure that the Clyde maintains its relative position. In order to study the effect of various proposals for improvements, a large scale hydraulic model involving the simulation of saline stratification and sediment movement has been commissioned by the Clyde Port Authority and is now being constructed and operated under the direction of Professor Frazer and Dr. Barr of the University of Strathclyde. This paper describes some of the field work carried out in conjunction with this model study in order that water and sediment transport may be correctly simulated.