 A notable Roman example were the excavated Nemi Ships with an underwater hull covered by a thin layer of lead.The practice was resumed by the Spanish and Portuguese in the Age of Exploration, while the British Royal Navy began to copper their war ships in the 1760s.The huge "Syracusia", built by the Greek tyrant Hiero II of Syracuse around 240 BC, featured bronze-clad mast-tops for marines and an iron palisade on its fighting deck against enemy boarding attempts.