Lack of suitable information about the fate of archaeological human bones in sea suggested that we should carry out a multidisciplinary investigation on the state of preservation of the skeletal remains of three individuals who were apparently drowned while sailing in Arabian ships wrecked during the 10th century A.D. off the Mediterranean coast of France. The bones and the slime which had penetrated into their cavities during their long period of submersion were investigated by the following methods. Bones: specific weight, histology, microradiography, electron microscopy, microscopy, microhardness, x-ray diffraction, calcium and phosphorus analysis, and 14C-dating. Slime: grain distribution, mineralogical analysis, and identification of microfauna and microflora. In spite of their long immersion in sea-water, the bones were, in general, well preserved. This is especially true of the organic bone matrix, whose histological and histochemical properties were like those of fresh bone. On the other hand, the inorganic fraction had increased, though its patterns corresponded to those of hydroxyapatite. Besides, some deterioration in the bones had been induced by unidentified microorganisms. All these findings and their genesis are discussed in detail.