"Britannia rules the waves!"

Back in the 1800s, Britain's bellicose boast might have been true -- but Britain's Royal Navy is fast disappearing from the world's oceans. Take the new "Type 45" stealth destroyer for example, the latest of which has a name with a familiar ring. 

One hundred years ago, the battleship HMS Duncan led a flotilla of six British battlewagons in WWI  that helped defeat the Kaiser, and swept the seas clear of German warships. Today, the "Duncan" is back in action ... but in the form of a smallish 7,500-ton  destroyer. (That's half the size of Japan's dread helicopter destroyers.)

Royal Navy battleship HMS Duncan, c. 1908. Source: Wikimedia Commons.

This past week, Britain's Royal Navy put  the "Duncan" name back on the rolls when it declared the vessel operational. The final ship in a group of six new Type 45 stealth destroyers, the Duncan carries just a single 4.5-inch Mk 8 naval gun, to the old battleship's 32 cannon. Supplemented with Boeing's (NYSE:BA) Harpoon anti-ship missiles, Aster anti-aircraft missiles, and two Phalanx Close-In Weapons Systems from Raytheon (NYSE:RTN), the new Duncan packs more of a punch than her battlewagon self -- but as part of a much diminished fleet.

Britain's amazing, ever-shrinking, navy
According to DefenseNews.com, the commissioning of the HMS Duncan marked the final step in a 13-year program to replace Britain's force of 16 Type 42 destroyers with just six Type 45s. It cost Britain $9.1 billion to build Type 45s. Cost overruns persuaded Britain to cut its planned purchase of 12 destroyers in half.

As a result, the British surface combat fleet now comprises just 19 warships -- 13 Type 23 frigates, and now six Type 45 destroyers. Its navy could shrink again when contractor BAE Systems (OTC:BAESY) begins the next fleet upgrade, replacing the Type 23s with a new Type 26 frigate. That project should commence in 2016. But if money remains tight, the Royal Navy may end up with fewer frigates than it began with, as well.

As the Royal Navy tells it, that's not a problem, because the new Type 45s have "more capability than the Type 42s" they replace. They're also supposed to be harder to kill, being equipped with stealth technology and a sleeker silhouette that makes them harder to spot on radar.

Here's how a Type 45 looks ...

HMS Daring, in profile. Source: Wikimedia Commons

Pretty svelte, huh? Now take a look at America's new Zumwalt-class destroyer for comparison:

USS Zumwalt. Source: U.S. Navy

Some reports indicate both ships have the radar signature of a fishing boat. But while the Daring, pictured earlier in this article, is definitely slimmed down from its battlewagon days, the Zumwalt looks downright knife-sharp. There's hardly a flat surface on her for a radar beam to bounce off of.

Pretty pictures. But what's the point?
The point is simply this: In theory, both the Zumwalt and Britain's Type 45 destroyers are better warships than the vessels they replace. But they both suffer from the technologically insurmountable fact that they can't be two or three places at once. A single ship cannot patrol for pirates off Somalia and enforce freedom of transit in the East China Sea while evacuating humanitarian aid workers from Syria.

This is a problem for the U.S. Navy -- but with 283 ships in service, the situation's not yet critical. Britain, in contrast, can just about count its warships on the fingers and toes of a single admiral.

What's the solution?
At the root of the problem, of course, is cost. In Britain, cost overruns resulted in only six Type 45s being built, when a dozen had been planned. Here in the U.S., plans to build 32 Zumwalt -class stealth destroyers should have kept defense contractors General Dynamics (NYSE:GD) and Huntington Ingalls (NYSE:HII) building ships for years. Instead, soaring costs cut the planned Zumwalt build to just three ships.

Technological wonders these ships might be. But thanks to their high cost, the primary effect of building "stealth" ships is that Western navies are becoming invisible on the high seas. Maybe what we really need is more low-tech, low-cost vessels. Else, Japan, India, and China will soon have to fill the void left by Britain's, and America's, vanishing navies.