Hyperspectral Remote-sensing reflectance data collected by the Finnish Environment Institute (SYKE) within the BONUS FerryScope project, analysed (quality checks and spectral filtering) at the Plymouth Marine Laboratory. Methods initially described in: The data were collected from merchant vessels Finnmaid (Finnlines) and Transpaper (Transatlantic). This data set is limited to records for the year 2016. Field data collection and processing: Simis, S.G.H., & Olsson, J. (2013). Unattended processing of shipborne hyperspectral reflectance measurements. Remote Sensing of Environment, 135, 202–212 Data quality control: Qin, P., Simis, S.G.H., & Tilstone, G.H. (2017). Radiometric validation of atmospheric correction for MERIS in the Baltic Sea based on continuous observations from ships and AERONET-OC. Remote Sensing of Environment, 200, 263-280 Data specification lat, lon - geographical latitude/longitude coordinates in decimal degrees time - timestamp (date+time) in UTC following ISO 8601 notation. (The location and time fields correspond to the start of a measurement) Rrs_001_3233 .... Rrs_193_9536 - Remote-sensing reflectance (Rrs, units 1/sr). The sequential numbering (1-193) denotes band number, the last term is wavelength x 10 in nm. For example Rrs_001_3233 is the 1st band centred at 323.3 nm. The wavebands approximate the native resolution of the 3-sensor system (TriOS Ramses ARC + ACC units) used to collect radiance and irradiance spectra of the sea surface and sky. Contributions: Stefan Simis, Jenni Attila, Mikko Kervinen, Kari Kallio, Sampsa Koponen, Sakari Väkevä maintained the in situ system. Stefan Simis developed the code to process the (ir)radiance data to Remote-sensing reflectance. Mikko Kervinen and Stefan Simis maintained the operational processing system Ping Qin analysed multi-year observation records and developed quality-control filters Silvia Pardo and Gavin Tilstone analysed the data against satellite sensor records.