The document discusses efforts to semantically annotate ocean observational data from the point of collection. This includes prototyping the annotation of SeaBird CTD data with RDFa and collaborating with sensor manufacturers to map file headers to SKOS concepts. The goal is to better describe and assess data quality for specific uses and enable (near) real-time linked data. Two approaches are outlined: building community semantics or reusing existing resources, with common ground being to embed semantics in OGC sensor web enablement documents.