Underwater archaeological sites have always been notoriously difficult to detect. This is also the case with any archaeological object that is for some reason buried in the benthic sediments, which has been observed to be quite common especially in shallow littoral zones and in protected marine bays with favorable conditions, since it would not be visible on the sea bottom. This makes the detection of such sites via trivial archaeological means like diving surveys nearly impossible, while other otherwise very powerful geophysical methods, like sonar imaging for example, have also been proven to be almost entirely ineffective. As a consequence of this the vast majority of the underwater archaeological sites in the Bulgarian Black Sea littoral zone have been initially discovered by chance mainly due to the development of large infrastructure projects. This puts these sites into serious danger and at the same time precludes any opportunities for their scientific study and subsequent presentation before the general public, although they usually bare high potential for future valorization due to their remarkably good state of preservation. Although some geophysical methods (like for example sub-bottom profiling – SBP and marine magnetometry) have been employed for the detection of UWCH sites, they are not universally applicable and have severe limitations. For example, SBP cannot effectively penetrate certain kinds of marine sediments, while the magnetometry cannot be counted on for the detection of non-metallic objects (like prehistoric settlements for example). For this reason, the expanding of the available geophysical methods suitable for such tasks would be of the highest priority. The electro-resistivity method has so far been extensively applied in geology and other engineering fields, but has found little application in marine archaeology due to the its relatively lower measurement resolution and some operability restraints in marine environments. Hence the, main goal of this sub-task is, while employing an existing commercial electro-resistivity measuring device, to develop effective methodology for its use for archaeological purposes.

In archaeological practice, there have always been cases for sampling the sediment at a relatively shallow depths of 1.2 to 4 meters. The information from the samples has a significant contribution to the understanding of the genesis of the surrounding environment, respectively of the archaeological site in different periods of time. Currently, these samples are taken either with traditional core probes, which are extremely expensive for archaeological purposes, or with small hand-held probes, which are often ineffective.

In archaeological practice, there have always been cases for sampling the sediment at a relatively shallow depths of 1.2 to 4 meters. The information from the samples has a significant contribution to the understanding of the genesis of the surrounding environment, respectively of the archaeological site in different periods of time. Currently, these samples are taken either with traditional core probes, which are extremely expensive for archaeological purposes, or with small hand-held probes, which are often ineffective.