When downloading OOI data, you have three file formats from which to choose: NetCDF, .csv, and JSON. More info on this and other data questions, can be found at: [https://oceanobservatories.org/knowledgebase/what-data-formats-are-available/]
If you use the ERDDAP server in the new Data Explorer tool https://dataexplorer.oceanobservatories.org/
the types of download files supported increases.