The　control　of　the　point　stabilization　of　an　underactuated　surface　ship　is　investigated.　Wave　forces　and　moment　impacted　on　the　vessel　are　considered　and　suppressed　by　L2-gain　design.　Combined　with　Lyapunov　function　and　backstepping　method,　a　time-invariant　nonlinear　feedback　control　approach　is　proposed.　Simulation　results　prove　the　good　performance　of　the　controller　proposed　for　the　stabilization　of　the　underactuated　system.　©　2021　IEEE.