Abstract: An apparatus and method for determining the effect of the configuration of an outer surface of an object on the drag of the object. The apparatus comprises a housing, an inner block suspended in the housing, a motor for rotating the housing, and a torquemeter. The inner block is connected to the torquemeter by a suspending rod and universal joint. The method comprises attaching a layer of material having a desired surface configuration to the inner block and to the housing, filling the housing with a fluid, and driving the motor so that the housing is rotated. The magnitude of the torque on the inner block is then measured by the torquemeter. The rate of rotation of the housing and the temperature of the water are monitored.