bathymetric and topographical survey for a length of 1450.00 m (cross section at 50.00 m interval) in between diamond harbour jetty and muktangan and sultanpur, mukundapur, harinarayanpur, dariratneswarpur, roytala area for consecutive two occation in connection with the periodical health cheek up of hooghly river and its left embankment under diamond harbour municipality, dist. - south 24 pgs. (for the period of six months)