NDBC THREDDS Server Catalog https://dods.ndbc.noaa.gov/thredds/catalog/data/ocean/42021/catalog.html

Dataset Size Last Modified
     Folder  42021   --
         42021o2009.nc 482.2 Kbytes 2009-12-31T23:40:00Z
         42021o2010.nc 758.9 Kbytes 2010-08-31T23:40:00Z
         42021o2011.nc 287.8 Kbytes 2011-05-31T23:40:00Z
         42021o2012.nc 564.8 Kbytes 2012-10-30T16:40:00Z

National Data Buoy Center THREDDS Server at National Data Buoy Center see Info
THREDDS Data Server [Version 4.6.14 - 2019-07-23T11:04:31-0600] Documentation