<p>Ancient Indian shipbuilding demonstrates that very high levels of naval architectural knowledge, material science and environmental adaptation were already in practice many centuries before the modern era. This paper reinterprets archaeological, textual and iconographic evidence from dockyards, ship remains and classical treatises through the lens of marine engineering. It analyses structural and functional features such as proportion-based hull ratios, compartmentalised construction, tropical hardwood selection, lashed lug joinery and natural antifouling coatings to extract engineering lessons relevant to modern sustainable ship design. It also evaluates ancient navigational practices, including astronomical orientation and monsoon driven route planning, as a systems engineering approach that integrates design, operation and environmental conditions. The findings identify transferable principles for today’s marine sector such as environmentally conscious hull optimisation, bio-based coatings, modular construction for repairability and adaptive material selection for harsh marine environments. By reframing India’s maritime heritage as a repository of engineering innovation, this study contributes to the development of greener, more resilient and culturally informed marine technologies.</p>