The debate over requirements definition and systems engineering continues to shape the procurement of complex naval vessels, where balancing operational needs, affordability, and technical feasibility remains a significant challenge. Growing recognition of the close relationship between requirements and design is driving calls for more integrated and iterative approaches to early-stage ship development.

Hybrid propulsion systems are attracting growing interest as shipowners seek practical pathways to improve energy efficiency and reduce emissions. This study demonstrates that battery-diesel-electric propulsion can be integrated into modern bulk carriers with minimal impact on cargo capacity, while careful system placement may also offer operational benefits through improved weight distribution and trim optimisation.

As environmental, safety, and regulatory expectations increase, ship recycling is under growing pressure to modernise and improve operational standards. The development of knowledge-based expert systems offers a means of supporting decision-making across the recycling process, helping stakeholders enhance safety, environmental performance, and management of increasingly complex ship dismantling activities.

As ship design projects grow in complexity, designers are increasingly seeking methods that can accommodate uncertainty and keep options open for longer. This research demonstrates how set-based design, supported by intelligent decision-support tools, can improve resilience to late-stage design changes, enabling more informed decisions and reducing the risk of costly redesign during development.

Slamming remains one of the most demanding load cases in marine structural design, with significant implications for vessel safety and durability. Improved numerical methods are enhancing the prediction of water-impact pressures and forces, providing deeper insight into the effects of hull geometry and impact conditions while supporting more robust structural assessments.

Improving confidence in damage-stability assessments depends on a clear understanding of how flooding progresses through complex internal spaces and how accurately this behaviour can be modelled. Growing reliance on numerical flooding simulations is increasing the demand for robust validation data, with full-scale experiments playing an important role in refining prediction methods and supporting more reliable survivability assessments.

The transition towards risk-based safety regulation is reshaping the way ship survivability is assessed, particularly for complex vessel types such as passenger ships. Growing industry experience with probabilistic damage-stability requirements is highlighting both the opportunities and challenges of implementing performance-based approaches, driving ongoing development of assessment methodologies, approval processes, and supporting design standards.

As propulsion systems become more advanced and manoeuvrability demands increase, understanding the loads acting on azimuth thrusters is essential for reliable vessel design. Greater insight into the influence of hull wake, operating conditions, and sea state is helping to improve the mechanical design and sizing of propulsion components, supporting more robust and efficient vessel operations.

Providing accommodation at sea has evolved into a highly specialised sector, with floating accommodation solutions adapting to a wide range of operational and environmental requirements. Growing demand for offshore support and waterfront development is driving the use of increasingly diverse flotel concepts, highlighting how vessel design must be tailored to location, operating conditions, and intended use.

Defining requirements for complex naval vessels remains one of the most challenging aspects of ship acquisition, requiring a balance between operational aspirations, technical feasibility, and affordability. Growing recognition of the iterative relationship between requirements and design is encouraging more integrated approaches to concept development, where stakeholder needs and potential solutions evolve together to inform better long-term decisions.

As physical and numerical modelling techniques become increasingly sophisticated, understanding the limitations of conventional scaling approaches is attracting renewed attention across marine hydrodynamics. Advances in the investigation of nonlinear wave phenomena, seakeeping behaviour, and sloshing effects are driving the development of enhanced testing methodologies, improving confidence in the translation of model-scale results to full-scale vessel performance.