In recent times several natural disasters hit some part of the coastal areas around the world in particular small islands and archipelagic countries causing hundreds thousands of peoples lost their lives.Moreover anthropogenic global warming will undoubtedly cause substantial sea-level rise and shoreline movement during this century and beyond. Learning from such kind of devastating disasters, it is important to have accurate, complete and up-to-dated spatial information resources and services of coastal area for better development planning and timely disaster management in which spatial data infrastructure (SDI) as an enabling platform can facilitate access and integrate of different datasets from different disciplines. However, current SDI design is focused mainly on access to and use of land related datasets or marine related datasets, with most SDI initiatives stopping at the land-ward or marine-ward boundary of the coastline, institutionally and spatially. Consequently, there is a lack of harmonised access to seamless datasets from marine, coastal and land-based spatial data providers. There is a growing and urgent need to create a seamless SDI model that bridges the gap between the terrestrial and marine environments, creating a spatially enabled land-sea interface to more effectively meet sustainable development objectives. This paper justifies the need for seamless information and proposes a seamless SDI model as an abstract level SDI at the higher level and its associated components followed by implementation strategy in order to develop an overarching architecture for a seamless SDI that allows access to and interoperability of data from marine, coastal and terrestrial environments.