The 2012 guidelines on the attained Energy Efficiency Design Index (EEDI) for new ships (MEPC.212(63)) represent a major step forward in implementing the REGULATIONS ON ENERGY EFFICIENCY OF SHIPS (resolution MEPC.203(62)). There are, however, serious concerns regarding the sufficiency of propulsion power and of steering devices to maintain the manoeuvrability of ships in adverse conditions, hence the safety of ships. This gave reason for additional considerations and studies at IMO (MEPC 64/4/13). Furthermore, whereas present EEDI regulations concern the limitation of toxic gas emissions by ship operation, what is a new constraint in ship design and operation, it necessary to look holistically into this and find the right balance between efficiency, economy, safety and greenness. The aim of the proposed research project is to address the above by: further development and refinement of high fidelity, hydrodynamic simulation software tools for the efficient analysis of the manoeuvring performance and safety of ships in complex environmental conditions; Performing seakeeping/manoeuvring model tests in combined seaway/wind environment for different ship types, to provide the required basis for the validation of results obtained by numerical simulations, whereas full scale measurements available to the consortium will be exploited; Integrating validated software tools into a ship design software platform and set-up of a multi-objective optimization procedure; Investigating the impact of the proposed new guidelines on the design and operational characteristics of various ship types; investigating in parallel the impact on EEDI by the developed integrated/holistic optimisation procedure in a series of case studies; development of new guidelines for the required minimum propulsion power and steering performance to maintain manoeuvrability in adverse conditions; preparing and submitting to IMO a summary of results and recommendations for further consideration.