This paper describes the unberthing of container ships using conventional and unconventional maneuvers. The research has been carried out in the Maasvlakte in the Port of Rotterdam (Netherlands). This research analyzes the departure of ships with the onshore wind (various weather conditions) without tug assistance. The analysis of unberthing maneuvers, taking into consideration external conditions, draft, and load onboard, is based on the knowledge gained from the theory and experience in the performance of unconventional maneuvers without the assistance of a tugboat. Challenges posed to the maritime industry by developments in shipbuilding technology are discussed. This paper also presents the specifications of the ships under analysis and describes quays at the Port of Rotterdam that have been adapted for the berthing of container vessels. Unberthing maneuvers are also explained in detail. Additionally, the optimum unberthing method to be used in the Port of Rotterdam is presented. The results provide recommendations for captains of vessels of similar navigational and operational parameters.