Adhesive coatings in naval archaeology: molecular and palynological investigations on materials from the Roman Republican wreck Ilovik–Paržine 1 (Croatia)

Introduction The construction of a vessel (from a boat to a large ship) and its maintenance requires waterproofing of its hull and protection against water corrosion and the aggression of microorganisms, worms and other pests. What could be more logical than using an easily accessible and applicable hydrophobic adhesive material? Many substances have been used over time such as resins, bitumen, plant tars, pure or mixed with beeswax, fats, inorganic elements. Pliny the Elder already mentions zopissa , a mixture of pitch and beeswax ( Natural History XVI, 23). The strong expansion of shipbuilding between the 13th and 19th centuries generated a veritable industry of plant tars. Methods In this research work, a new interdisciplinary approach involving the combined use of molecular, palynological and statistical indicators has been implemented to characterize ancient waterproofing materials. This analytical strategy opens new fields of investigation in naval archaeology. Results and discussion Beyond the characterization of materials (nature, manufacturing processes, naval techniques, degree of alteration), it especially reveals information about the surrounding vegetation during the production or the application of the waterproofing material. This approach has been applied to the study of the protective coating of the Roman Republican wreck Ilovik–Paržine 1 (around the middle of the second c. BC) found in Paržine Bay (Ilovik Island, Croatia).