The new capital ships are the nuclear submarine and aircraft carrier. But for an old black shoe sailor like myself, those are not really ships at all.

The capital ship, the battleship (BB), the big gun platform designed primarily for defeating its own counterpart in fleet action, has proven too vulnerable and expensive. No navy today has any.

The cruiser(CA & CL) still remains in the order of battle, but is also diminishing in numbers for many of the same reasons.

The increasing lethality, accuracy and range of weapons and improved communications and coordination has made the destroyer (DD) the backbone of modern navies. Originally a specialized type designed primarily as a counter to torpedo boats (their original name was 'torpedo boat destroyer') has now become the workhorse of the fleet. Of course, they have become much larger and more capable, and are specializing for specific missions, such as antisubmarine warfare, anti-aircraft protection, pickets, scouts, patrol and escort work.

My own destroyer, built in 1959) was already the size of a WWII light cruiser, and it was soon downgraded from "Destroyer Leader, Guided Missile (DLG)" to "Destroyer, Guided Missile" (DDG) as larger and more powerful destroyers took over its role as all-purpose combatant and aircraft carrier escort. It was originally designated a "frigate", although that term is now being reassigned be follow European naming conventions. Frigates are now small destroyers, what in WWII used to be called "Destroyer Escorts" (DE) in USN, and corvettes in NATO.

The three main classes, battleships, cruisers and destroyers, are what used to be called in the days of sail ships-of-the-line, frigates and corvettes.

And alas, as in science fiction space navies, ships no longer slug it out with guns within sight of each other. Engagements are now carried out over the horizon, and fleets (like an aircraft carrier battle group), are now spread out over an area of ocean the size of Texas.

Its not like the Old Navy.