Many regions including Europe, the USA, Australia and Canada are making significant progress in facilitating the discovery, access and long-term stewardship of marine data through the development, implementation and operation of national, regional or international distributed ocean observing and data management infrastructures such as SeaDataNet, EMODnet, IOOS, R2R, and IMOS. The Ocean Data Interoperability Platform (ODIP) project, supported by the EU Framework Programme 7 (FP7), National Science Foundation (USA) and Australian government, was initiated 1st October 2012 and continues as ODIP II for another 3 years with EU HORIZON 2020 funding. ODIP includes many of the major organizations engaged in ocean data management in Europe, US, Australia and Canada. ODIP is also supported by the IOC-IODE, closely linking this activity with its Ocean Data Portal (ODP) and Ocean Data Standards Best Practices (ODSBP) projects. The ODIP coordination platform aims to establish interoperability between the regional marine data management infrastructures and also with relevant global systems e.g. GEOSS and POGO. This is being achieved by facilitating organized dialogue between the key e-infrastructure representatives through a series of international workshops and fostering the development of common standards, best practices and interoperability solutions. This approach is being evaluated and tested by means of three prototype development tasks. The first prototype (ODIP 1) is focused on establishing interoperability between the SeaDataNet, AODN and US NODC data discovery and access services using the GEO-DAB brokerage service. This addresses not only the repository interoperability in terms of data and metadata formatting, but considers interoperability between data from different ocean disciplines. The second prototype (ODIP 2) furthers deployment and interoperability between cruise summary reporting (CSR) systems in Europe, US and Australia, and exposure of the cruise summary reports in the POGO portal. The third prototype focuses on Sensor Observation Services (SOS) and developing common standards for SensorML and O&M profiles for selected sensors (SWE). These prototypes are playing a role in advancing important elements of interoperability. The next step is the adoption of these solutions by the broader ocean community. The presentation will give further background on the ODIP projects and the latest information on the progress of the three prototype development tasks and other issues in the ocean and marine community such as implementation of persistent identifiers and other means to significantly improve discovery, access and long-term stewardship of ocean and marine data.