This dataset provides data from various air quality sensors at a floating platform of the Federal Institute of Hydrology (BfG) at the river bank of the Rhine in Koblenz, Germany. The data was collected as part of the mFUND project "REIN" which investigated the suitability of low-cost sensors for the determination of ship emissions with high spatial and temporal resolution. Measurement data involves various pollutants, including nitrogen oxides (NO, NO2), carbon dioxde (CO2), particulate matter (PM2.5) mass concentration, black carbon (BC) mass concentration, ultrafine particle (UFP) number concentration and particle size distribution. Averaged data is provided at 1 minute and 1 hour temporal resolution and covers both low-cost and reference instruments. Additonally, analysed ship peaks are presented. The dataset is related to the publication "Applicability of compact low- and mid-cost sensors to monitor air pollutant emissions from inland ships (Aerosol and Air Quality Research)".