Boat builder Amol Mondal (L) and father Panchanan (centre) check the balance of the hull after completion of main hull planking. They run a split bamboo cane to a corresponding point on the current sheer line from a datum on a longitudinal overhead datum line that is directly above one of the datums marked on the keel at the time of the keel-and-post balancing process. They will do this starboard and port, and compare the distances as an indicator of the degree of symmetry and need for correction. Brother Dilip (R) looks on.