A new correction procedure for shallow-water effects in ship speed trials

To correct ship speed trials for limited shallow-water effects, Lackenby’s method is currently recommended by the ITTC. This method appears to be based on very few and inadequate data. To replace it, a new procedure is proposed. It corrects separately for the effects of shallow water on the different components of ship resistance. These have been identified by computational studies.A simple algorithm is proposed to estimate a power increase for equal speed in shallow water. This new correction method has been applied to dedicated shallow-water trials for two ships and was found to perform much better than Lackenby’s method.