Floating structures have raised interest in the recent years for different applications, from living and farming at sea to renewable energy production. To support the logistics on the float- ing structures, floating cranes are necessary and their designs are constantly improved. In- creasing developments in the automation industry paved the way for automated crane opera- tions. In this work, motion control of a smart crane is presented with particular attention to the performance under wave motion. In this research, a scaled down, two-dimensional math- ematical model of a gantry crane is derived using Lagrangian mechanics and DC motors dy- namics. This results in a nonlinear system that is capable of simultaneous traversing and hoist- ing a container. The system is simulated in MATLAB Simulink environment and a proportional-derivative control and a state feedback control are designed and implemented. Their robustness is explored by modelling sensor behavior, external disturbances and floating platform dynamics. Both control strategies were able to keep stability in a disturbed system. During simulation, the sway angles never exceed 10 degrees. Smaller oscillations occurred us- ing the state feedback control. Therefore, it creates a smoother response compared to the pro- portional derivative control, which ultimately translates to increased safety, turnover rate and durability of the crane.