The reduction gear ratio ensue that the require thrust is delivered to the boat by the propeller without overloading or over speeding the main engine. This ratio depends on the resistance of the hull, the main engine specifications, and the propeller characteristics – pitch and diameter inclusive. This work carries out a regression analysis on existing tugboats relating main tug boat parameters against their reduction gear ratio. This is in other to determine the optimum gear ratio basing on the experience from the existing tugboats. Interesting recommendations emerging from this work will help in the proper matching of the propeller to the main engine power for tug boats.

Keywords : Tugboats, Main Parameters, Reduction Gear Ratio, Regression Analysis, Recommendations.