The "BOUée pour l'acquiSition d'une Série Optique à Long termE" project (BOUSSOLE), can be translated from French as the “buoy for the acquisition of a long-­‐term optical series." It involves monthly servicing cruises to an offshore site between Nice and Corsica where a buoy dedicated to radiometric measurements acquires data continuously. During these visits, the activities are dedicated to the buoy servicing and to the acquisition of complementary data such as vertical profiles of radiometric quantities, phytoplankton pigments (HPLC), particulate absorption (filter pad technique), total suspended matter etc…(Antoine et al., 2006). These latter three parameters are obtained thanks to in situ sampling of seawater at 11 depths throughout the euphotic layer using rosette and CTD deployments. The present work focuses on the comparison of the filter pad particulate absorption data obtained from two different spectrophotometers. With the acquisition of a new Perkin Elmer lambda 850 spectrophotometer at the LOV, it was important to ensure continuity in the measurements done in the frame of the BOUSSOLE time series, before passing from one older instrument, which is not used for BOUSSOLE measurements anymore since November 2011 to a new and more sensitive one.