The history of naval fleets makes for one of the most fascinating subjects for the serious armchair historian. Until very recently, it was the power--inferred or actual--of the naval fleet which assured a nation's security. Though most contemporary militarists concentrate first on air- and ground-superiority, even today the strength of a naval fleet can be every bit as influential as a land army.

In some countries, the word ''fleet'' isn't meant to suggest a single squadron of warships, but rather the entire navy. Not surprisingly, this does not apply to the United States, United Kingdom, and Russia--all of which have multiple fleets within larger navies.

In terms of identifying a fleet by title, most countries in the world name theirs after the ocean or sea in which each is dedicated. However, the United States prefers a numbered--rather than a named--system. Fleets which are even-numbered refer to those in the Atlantic ocean; those which are odd-numbered refer to those in the Pacific.

Researching naval history can be eye-opening even to those who consider themselves established ground-war authorities already. The heroes and heroics on both sides are stunning, the battles terrifying, and the human stories rich and compelling. As with all military history, sometimes the more we learn, the more we discover that wins and losses were rarely ''obvious from the start.'' In many of the most famous sea battles, such as WWI's Battle of Jutland between Germany and Great Britain, the outcomes were far from clear-cut.

For many, this is the most extraordinary aspect of history: discovering how close many key battles were, and how easily victory could have gone to the competitor, rather than the other way around. Eye-opening and thought provoking, videos, books and journals about naval fleets--contemporary and historical--provide a fascinating window into history.