Ancient Roman Shipwreck Reveals Waterproofing Techniques

Scientists have analyzed a 2,200-year-old Roman shipwreck, revealing how its hull was waterproofed and repaired. The Ilovik-Paržine 1 shipwreck, found off the coast of Croatia, contained coatings of pine tar and a mixture of tar and beeswax. Pollen trapped within these ancient materials provided clues about the landscapes where the ship was constructed or mended.

Researchers used molecular and pollen analysis to identify the coatings. Mass spectrometry identified compounds associated with pine trees in all ten samples. One sample also contained beeswax, a mixture known as *zopissa* to Greek shipbuilders. This combination improves adhesive flexibility and ease of application.

The sticky nature of the pitch preserved pollen from nearby vegetation. This allowed researchers to determine the types of plants present when the coatings were produced or applied. The pollen indicated environments typical of Mediterranean and Adriatic coasts, including forests of holly oak and pine. Matorral shrublands, with olive and hazel trees, were also represented. Alder and ash pollen suggested riverbank and seashore vegetation. Small amounts of fir and beech pollen pointed to mountainous regions along the north-eastern Adriatic coast.

The analysis suggests the vessel received four to five separate coating applications over its lifetime. The stern and central sections had consistent material. The bow, however, showed three distinct coating batches. This pattern indicates the ship underwent repeated repairs. Materials were likely sourced from various locations across the Mediterranean.

Earlier research on the ship's ballast suggested its construction in Brundisium, now Brindisi, Italy. The new pollen evidence supports some coatings being applied there. Other layers may have been added along the north-eastern Adriatic coast, near the wreck's discovery site. This study highlights the importance of organic waterproofing materials in understanding ancient naval technologies.