This paper proposes an event-triggered trajectory tracking control approach for fully actuated surface vessels based on guidance-control structure. In which, a guidance system is designed to provide the desired trajectory with an exogenous input while a control system is designed to guarantee uniform ultimately bounded tracking error and to ensure no Zeno behavior of execution times. The proposed approach reduces the amount of computation and communication, and in the meantime it results in little controller executions. The effectiveness of the approach is finally illustrated by the simulation results.