This international standard provides summary of recommended methods for the determination of liquid flow in tidal channels , special consideration being given to those techniques that are either unique to or particularly appropriate for application under tidal conditions , including treatment of uncertainties. Reference is also made where appropriate, to methods for the determination of flow in non-tidal channels , but attention is drawn to their limitations with respect to practicality and/or uncertainty. This international standard does not describe altemative methods , such as the use of weirs , flumes , dilution gauging , salt velocity and floats, although they might be suitable under certain conditions , especially where the effect of tides only impedes and does not stop or reverse the passage of stream flow. These methods are described in detail other international standards