This technical report presents an overview of the ocean data ecosystem, detailing its key components and challenges. The oceans, which cover about 70% of the Earth's surface, are crucial for climate regulation and biodiversity, yet the growing complexity of ocean data poses significant challenges for scientific research and policy-making. The report aims to create a navigable map of the ocean data sector, utilizing the concept of a 'data ecosystem' to describe the various actors, organizations, and infrastructures involved in the data value chain. It proposes a structured model consisting of five key elements: stakeholders, societal elements, interoperability tools, data sources, and emerging solutions. The report also analyzes current ocean data sources and standardization efforts, emphasizing the need for effective data management and integration to enhance ocean research capabilities. By addressing the gaps between data producers and users, the report seeks to facilitate better utilization of the vast ocean data available for scientific inquiry.