High-resolution position data of the buoys used in the Seychelles purse seine fishery during 2015-2018 were made available from the companies ALBACORA, ATUNSA, ECHEBASTAR, INPESCA, PEVASA, and SAPMER to the Seychelles Fishing Authority (SFA) in spring 2019. The data set provides information on the number of floating objects monitored by each fishing vessel on a daily basis and enables to address the mandatory statistical requirements of the IOTC (Resolutions 18/01 and 18/08). The objective of the present report is to describe the data sets respectively collated from AZTI-Tecnalia and IRD for Spanish-owned and French-owned vessels and the methodology used to process the data to make them available for both compliance and scientific purpose.