Specifies functional requirements of sounding and suspension equipment used in the direct measurement of depth and velocity of flow in open channels, including the collection of sediment samples. It applies to equipment used for sounding of water depth by the direct method and to equipment for suspending measuring or sampling instruments (for example, current meter or sediment sampler) at the point of measurement. It does not apply to indirect methods such as echo sounding. It is identical with and has been reproduced from ISO 3454:1983.