This work presents 42 equations, result of regression analysis between main particulars and screw propeller pitch values for numerous existing tugboats of the world. The correlation coefficients of these regression analysis were upto 0.8 and above. This work enable the selection of screw propeller pitch and diameter for projected or existing design of tugboats at early stage of design of the boat and aid in reduction of the iterative processes in the hydrodynamic sizing of the scew propeller at the advanced design stage. Sample computation using this method for three existing tugboat show 5.3%, 8.9% increase and 18.3% decrease in the predicted pitch values compared with the actual pitch values of the screw propellers of the respective sample tugboats.

Keywords : Tugboat, Propeller, Pitch, Diameter, Hull Particulars, Correlations, Formulas.