This dataset contains raw and processed reflection seismic and sub-bottom profiles from the southwestern Algarve shelf, Portugal. The profiles were recorded in January 2020 during a campaign onboard HSV FISÁLIA of the Portuguese Navy for project OnOff "Coupling onshore and offshore tsunami record: complementary tools for a broader perspective on tsunami events", funded by FCT (Portuguese Foundation for Science and Technology) grant PTDC/CTAGEO/28941/2017. The first folder (seismic profiles) compiles all reflection seismic profiles recorded with a centipede sparker source designed by RCMG at Gent University, Belgium, and a SIG single-channel streamer receiving unit. The center frequency of the signal was around 600 Hz, with a sampling frequency of 16 kHz, a shot interval of 0.5 s, and an approximate vertical resolution of ~50 cm. Basic post-processing included burst noise removal, amplitude correction, bandpass filtering, and top muting. The dataset contains raw data as .NAV (with coordinates), .PRM and .SEG files and processed data as Label_processed.sgy files with Label_pick.txt files for seafloor picks. The second folder (sub-bottom profiles) compiles all sub-bottom profiles recorded with an Innomar SES-2000 quattro system. This system consists of four individual transducers functioning as seismic sources and receivers. It was used in single-beam mode with a sampling frequency of 8 kHz. The shot interval during the survey was not set to a specific value but automatically optimized by the system as a function of the water depth. As a result, the ping rate changed slightly around 7-8 pings/s. The theoretical vertical resolution was around 5 cm. Basic post-processing included burst noise removal, amplitude correction, swell filtering, and top muting. The dataset contains raw data as .txt (with coordinates), .PRM, .raw and .sgy files and processed data as Label_processed.sgy files with Label_pick.txt files for seafloor picks.