flThis report describes how the PROVOR and ARVOR oats work close to the sea surface and gives some recommendations on the real time QC tests that should be applied to the near surface salinity and temperature data. The CTD collects discrete (P,T,S) triplets every 10 s but the data is bin-averaged before being transmitted by satellite. Within a slice, instantaneous measurements are rst decimated, keeping triplets that are distant by more than 0.5 dbar and then averaged. Means are calculated using the data at the full resolution available (1 cbar for pressure) and rounded to the transmitted resolution (generally 1 dbar for pressure for ARGOS satellite system, 1 cbar for IRIDIUM). PROVOR and ARVOR floats acquire temperature and salinity data all the way up to the sea surface. However, when the oat reaches the surface (generally 5 dbar), the CTD pump is switched o to prevent the sensor from being damaged. Unpumped salinity data -or partially pumped for some bin-averaged- are of dubious quality. The test that allows to separate the unpumped or partially pumped data from the pumped ones is given in this report. Temperature data obtained when the CTD pump is turned o is not problematic, but those acquired in the rst bin closest to the sea surface at pressure smaller or equal to 1 dbar may contain some mixed air/water measurements. The data quality of these mixed air/water measurements cannot be determined in real-time.