In the Zeeschelde (Belgium), a highly dynamic estuary, a range test was performed with eight acoustic receivers, each containing a built-in transmitter. The receivers were placed at 50 m, 200 m, 300 m, 400 m, 500 m, 600 m and 1000 m from the starting receiver, leading to various inter-receiver distances. The study took place for 10 weeks in spring 2020. Receivers were moored on the bottom with a concrete block to keep them at a fixed position. A bouy held them upright in the water but prone to tilt due to changing water currents.