: Earth Observations (EO) collect various characteristics of the objective environment using sensors which often have different measuring, spatial and temporal coverage. Making individual observational data interoperable becomes equally important when viewed in the context of its expensive and time-consuming EO operations. Interoperability will improve reusability of existing observations in both the broader context, and with other observations. As a demonstration of the potential offered by semantic web technology, we have used the National Oceanography Centre Southampton’s Ferrybox project (where suites of environmental sensors installed on commercial ships collect near real time data) to set up an ontology based reference model of a Collaborative Ocean, where relevant oceanographic resources, such as sensors and observations, can be semantically annotated by their stakeholders to produce RDF format metadata to facilitate data/resource interoperability in a distributed environment....