Historical usage 
Not all states gave their naval commanders such a title. Athens, for instance, placed its fleet under the command of generals (strategoi) holding the same title as those who commanded its land forces. Such command structures reflected the fact that, especially early in the Classical period, fleets operated in close conjunction with land forces, and indeed, the title of navarch did not begin to appear until the time of the Peloponnesian War, when fleets began to operate more independently. This separate title was originally used in cities that lacked an established naval tradition, Sparta being the most prominent, but entered broader use later, being adopted by the navies of the Hellenistic era states such as Macedon, Syracuse, Ptolemaic and Seleucid Empire, Achaean League, and Rhodes.
At Sparta and many other city-states, the position was held for one year only (a situation that compelled the Spartans to resort to an elaborate legal fiction when they wished to reinstate Lysander for more than one year in command). Admirals of despotic or monarchic states, however, could serve for years at a time. At Sparta, the position, unlike most high-level offices, was available to men from outside the Spartiate class; Lysander, the most famous occupant of the office, was a beneficiary of this rule.
Nauarchus, a direct transliteration of the Greek term into Latin, was also used by the Roman Navy for its squadron commanders. The Greek-speaking Byzantines sometimes used the term to designate the captains of ships; the terms drungarios or strategos were used to designate their admirals.
In the modern Hellenic Navy, Νávarchos is the highest rank, equivalent to full Admiral. It is held only by the Chief of the General Staff of National Defence, when he is a Navy officer. All but one of the remaining flag ranks are also derivations of this word: Antinávarchos (Αντιναύαρχος, Vice Admiral) and Yponávarchos (Υποναύαρχος, Rear Admiral), while Archiploíarchos is the equivalent of Commodore. The same ranks are also used by the Hellenic Coast Guard.
- Hornblower, Simon, and Anthony Spawforth ed., The Oxford Classical Dictionary (Oxford University Press, 2003) ISBN 0-19-866172-X