The first thing you're gonna need is an Optical Time Domain Reflectometer. Engineers on shore use it to send light pulses down the cable, which reflect back at the breakage point, providing a measurable delay that can translate to distance within "tens of meters."

Once you get your location guestimation, you posse up your team of about 50 people and pile them onto—what else?—a cable ship. This ship will need remotely operated vehicles ROVs (see James Cameron) that you drive down to the sea floor, roving around until you spot your breakage.

When the ROV finds the affected cable segment, it may snip off the nasty bits (just leaving them there to become part of somebody's new habitat) and bring up the two new ends. On board the ship, operators can splice a new segment between the cleanly trimmed ends of the cable break, and drop it back down.

Sometimes the ROV can't find the segment, or can't get the right grip on it. In these cases, the technicians send down a centuries-old device called a grapnel. The grapnel snags the cable wherever it can, and yanks it up to the boat for the end trimming and the repair job.

The cable itself is a tricky fix, because it is made up of nine layers, which you can see in the BBC's diagram below. If you are an experienced undersea-cable repairman who would like to add anything to this admittedly brief primer, I encourage you. And for the love of Pete, don't try any of this cable repair stuff at home! [BBC News]

The cables, branded Flag Telecom and SEA-ME-WE 4, for "Southeast Asia, Middle East, Western Europe", were severed in their runs between Palermo, Italy and Alexandria, Egypt. Data is being rerouted, in some cases "around India and back through Asia to the U.S." Outages or lousy connections have been experienced in India as well as Egypt, Dubai, Kuwait, Bahrain, Qatar and Saudi Arabia. (Insert sheik-surfing-the-porno joke here.)

According to the AP story, "There has been speculation...that an illegally or improperly anchored ship caused the problem. Our best guess is Godzilla of course, but some sort of Bond villain may be to blame. (Insert Dick-Cheney-not-ruling-out-terror joke here.)

Update: Mystery solved? This article, dated Jan. 30, seems to have clear information on the shipping debacle that caused the havoc:

"For some reason ships were asked to anchor in a different place to normal - 8.3km from the beach. One of the ship's anchors cut our cable but there are multiple cuts—we're not the only company having problems," says a Flag Telecom spokesman.