The intensity of water current and the nature of mixing at the surface, middle and bottom of fifteen fixed stations in the Cochin Harbour re discussed with respect to the tide. Water circulation cells known as gyre which facilities localised silting was identified at specific regimes of the channels. The maximum water flow is observed at the southern tip of Cochin cut (during monsoon). The inter-relationship between depth and water current is studied by the regime approach and the characteristic scatter diagram of the above parameters are presented.