Two divers submerged in the Mediterranean Sea for 30 years: persistence of adipocere and implications for postmortem submersion interval estimation.

Estimation of the postmortem submersion interval (PMSI) remains challenging in bodies recovered from aquatic environments, particularly after prolonged submersion and in the presence of adipocere. We report the cases of two divers who disappeared during the same accident in the Mediterranean Sea in December 1993 and were recovered 30 years later at depths of 103 and 113 m, 13 m apart. Both bodies underwent whole-body postmortem computed tomography, external examination, autopsy, toxicological analyses, and genetic identification. Both showed advanced skeletonization predominantly affecting the upper body, associated with persistence of adipocere-like tissues in the pelvic regions and lower limbs. However, the quality of soft-tissue preservation differed markedly: in X1, residual tissues were largely disorganized and consisted of yellowish-to-brown aggregates, whereas X2 showed more extensive preservation of the skin, hair, and discernible muscle masses in the lower limbs. X1 wore a two-piece semi-dry wetsuit, whereas X2 wore a full dry suit; these differences in preservation are discussed in relation to the characteristics of the diving equipment and local microenvironmental conditions. Pelvic tissues compatible with adipocere showed attenuation values ranging from - 100 to - 40 Hounsfield units. Genetic identification was achieved from muscle in X1 and from femoral bone in X2; toxicological analyses were negative. These observations illustrate regional and interindividual variability in preservation after the same 30-year marine PMSI and highlight the limitations of estimating PMSI solely on the basis of the macroscopic appearance of the bodies.