Abstract
In this paper, the results of several geophysical surveys developed with a Sub-Bottom Profiler in different regions of Spain are presented. This research forms part of a broader project aimed at developing innovative non-invasive methodologies for documenting Underwater Cultural Heritage (UCH). The 2001 UNESCO Convention on the Protection of the Underwater Heritage recommends the use of non-destructive techniques, in situ conservation, and prioritising exploration over recovery. Geophysical techniques allow the non-invasive documentation of UCH without altering archaeological remains. The Sub-Bottom Profiler was tested in several underwater archaeological surveys under different objectives, depths, and environmental conditions. The research questions addressed the amount of information obtainable without intrusion and the optimal use of the equipment for methodological innovation. Based on the results, methodological conclusions are drawn regarding the influence of seabed composition on acoustic performance, the importance of controlling navigation speed and vessel stability, and the strong impact of sea state on data quality. The need for frequency and motion-correction optimisation to balance resolution and penetration is also highlighted, as well as the usefulness of SBP for anomaly detection, site monitoring, and palaeolandscape reconstruction. These findings contribute to establishing a transferable methodological framework applicable to other case studies.