In the nearshore construction,the crane vessel and the transportation vessel are normally under the ship to ship condition with a T-shaped berthing during the lightering operation at sea.The vessel motion response under such condition is studied.Two common construction ships in the field of offshore wind power construction in China are selected,and the frequency domain analysis method is carried out to calculate significant valves of the transportation vessel motion response with the consideration of interactions between two ships.The results reveal that when the transportation vessel faces the waves,the transportation vessel motions are significantly greater than the its motions when the crane vessel faces the sea.However,the disturbance on the crane vessel by the transportation vessel is subtle.In the meanwhile,the clearance between the two ships are ignorable to the motion response of the transportation vessel.For the cargo with different lifting point heights,different wave-facing strategies can be applied when the crane vessel and the transportation vessel are under the ship to ship condition with a T-shape configuration during the lightering and linking operation.For the higher lifting point case,the relative motion between the hook and the lifting point can be effectively curtailed when the crane vessel faces waves.When the lifting point is located near the deck of the transportation vessel,the transportation vessel facing waves may be preferable for short period wave conditions,the transportation vessel is a floating breakwater for the crane vessel in such a condition,effectively curtailing wave energy transmitted to the crane and relative motions between the hook and the lifting point.