Monitoring the quality of river water in real time is critical for protecting aquatic life, public health, and the sustainability of our freshwater resources. A Floating Online Monitoring System enables continuous, remote measurement of key water parameters—like pH, dissolved oxygen (DO), turbidity, and contaminants—right at the water’s surface. For this purpose, an automatic, remote measuring station was developed, intended for installation on the floating platform. It is designed for not only collecting and archiving information about the ecological situation along the river, but also periodically forwards the data to a communication server.