According to historical accounts, the navy of Xerxes consisted of 4,000 organized units, including 1,207 triremes (three-tiered ships), each with rows of oarsmen on every level. These ships, called warships, had sharp prows designed to ram and destroy enemy vessels. The remarkable strength of navy is further demonstrated by an order from Xerxes, in which a group of ships under the command of Ariobarzanes sailed around Africa to deliver goods and troops to the coasts of Greece and the Mediterranean, accomplishing this extraordinary journey three times.
The Achaemenid era were also the first to connect the Red Sea to the Mediterranean Sea through canals and branches of the Nile River. The Achaemenid period were also the first to use divers in naval warfare, particularly during battles with the Greeks, including the Battle of Salamis. In the history of diving, are recognized as the first people to make use of underwater operatives.
