This section concerns subsurface profiling floats (also called Argo floats), expendable bathythermographs (XBT soundings ) and ship based instruments. Related alphanumeric codes are FM63 BATHY and FM64 TESAC.
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BUFR template used for ship based profiling instruments data is TM315007. GTS headers should also probably start with character string 'IOS' (information to be checked).