The

measurements near CRS Lubiatowo were carried out using a motor boat with a length of 5 m and a draught of 0.3 m. The boat’s position was determined using GPS Magellan. The StrataBox signals were recorded by the application of software StrataBox ver. 3.0.6.2, enabling simultaneous registration of the seismo-acoustic data and the geographical coordinates of the points surveyed. Figure 5 shows a photograph of the boat and the StrataBox transducer (before being lowered into water). During the two-day long survey (19–20 May 2009) tens of files with seismo-acoustic signals were recorded. The aim of these measurements was to test the equipment and tune parameters (e.g. setting the optimal signal gain). The actual profiling survey Y-27632 was carried out on 20 May, in a direction approximately perpendicular to the shoreline, from the depth of about 13 m (starting point of the profile – 54°49.561′N, 17°49.823′E) to the nearshore shallow water region (end of the profile – 54°48.867′N, 17°50.322′E). The measured bathymetric cross-shore profile was found to have the same shape as the sea bottom transect shown in Figure 4. In the

area where bars occur (at depths less than 8 m), where considerable changes in the sea bed take place not just at the scale of years but at the scales of months and weeks, the measured depths were slightly different than the ones in Figure PI3K inhibitor 4. The maximum discrepancies between the sea bottom ordinates measured in May 2009 and those plotted in Figure 4 are 2 m. The results at long distances from the shoreline, at water depths exceeding 10 m, indicated the presence of homogeneous sandy sediments in the sea bed. More interesting results were found closer to

the shoreline. Excerpts 6-phosphogluconolactonase of the StrataBox seismo-acoustic record of the surveyed profile are shown in Figure 6, Figure 7 and Figure 8. The record at 9 m depth (Figure 6) shows the boundary between two types of sediments. The data from drill core B (cf. Figure 4) suggest that the device has detected a local structure of the sea bed, consisting of a 3 m thick layer of marine sands above glacial sands. The measurements carried out in the vicinity of the gently-sloping outer bar at a distance of about 750 m from the shoreline (Figure 7) reveal the presence of weakly shaped boundaries between sands of various kinds and various origin. The echo reflected from the boundary at the –11.0 m ordinate may imply the existence of a distinct interface between the marine and glacial sands (see the drill core C in Figure 4). The profiling survey carried out in a deep trough between the bars located about 300 m from the shoreline (Figure 8) revealed layers which, on the basis of the data of Figure 4, may correspond to organic-bearing sediments (peat, sandy peat, mud, etc.).