Objective:

To analyze waterproofing residues from a 2,200-year-old Roman shipwreck to understand the vessel's repair history and the materials used.

Key Findings:

• All analyzed coatings were based on conifer-derived materials, likely heated resin or wood tar.
• Diagnostic diterpene markers indicated heat-treated Pinaceae material.
• One sample contained beeswax markers, suggesting a pitch–beeswax mixture.
• Statistical analysis revealed four to five distinct coating batches across the wreck.
• Pollen assemblages indicated Mediterranean coastal and valley environments, with some samples linked to Brundisium.

Interpretation:

The distinct coating batches suggest successive repairs using materials sourced from different locations, reflecting local shipbuilding and repair traditions.

Limitations:

• Alteration of archaeological samples may have affected molecular profiles.
• Limited number of samples may not represent the entire vessel's repair history.

Conclusion:

The study highlights the importance of organic waterproofing materials in understanding ancient naval technologies and local shipbuilding practices.