Cryptonomicon

A flock of white Vs migrates north from Gibraltar across a sunlit sea. At the apex of each V is a nitlike mote. The motes are ships, hauling megatons of war crap, and thousands of soldiers from North Africa (where their services are no longer needed) to Great Britain. That's how it looks to the pilots of the airplanes over the Bay of Biscay. All of those pilots and all of those planes are English or American--the Allies own Biscay now and have turned it into a crucible for U-boat crews.

Most of the Vs track straight parallel courses northwards, but a few of them curl and twist incessantly: these are destroyers, literally running circles around the plodding transports, pinging. Those tin cans will protect the convoys; the pilots of the airplanes who are trying to find U-691 can therefore search elsewhere.

The powerful sun casts a deep shadow in front of each ship; the eyes of the lookouts, irised down to pinpoints and squinting against the maritime glare, can no more penetrate that shade than they could see through plywood. If they could, they might notice that one of the big transports in the front rank has got some kind of unusual attachment: a pipe sticking vertically out of the water just in front and to one side of its bow.

Actually it is a cluster of pipes, one sucking in air, another spewing diesel exhaust, another carrying a stream of information in the form of prismatically reflected light. Follow that data stream a few yards down into the water and you will enter the optic nerve of one Kapitänleutnant Günter Bischoff. This in turn leads to his brain, which is highly active.

In the age of sonar, Bischoffs U-boat was a rat in a dark, cluttered, infinite cellar, hiding from a man who had neither torch nor lantern: only two rocks that would spark when banged together. Bischoff sank a lot of ships in those days.

One day, while he was on the surface, trying to make some time across the Caribbean, a Catalina appeared out of nowhere. It came from a clear blue sky and so Bischoff had plenty of time to dive. The Catalina dropped a few depth charges and then went away; it must have been at the end of its range.

Two days later, a front moved in, the sky became mostly cloudy, and Bischoff made the mistake of relaxing. Another Catalina found them: this one used the clouds to conceal his approach, waited until U-691 was crossing a patch of sunlit water, and then dove, centering his own shadow on the U-boat's bridge. Fortunately, Bischoff had double sun sector air lookouts. This was a jargonic way of saying that at any given moment, two shirtless, stinking, unshaven, sunburned men were standing on the deck, casting shadows over their eyes with their outstretched hands. One of these men said something in a quizzical tone of voice, which alerted Bischoff. Then both lookouts were torn apart by a rocket. Five more of Bischoffs men were wounded by cannon fire and rockets before Bischoff could get the boat under the surface.

The next day, the front had covered the sky with low blue-grey clouds from horizon to horizon. U-691 was far out of sight of land. Even so, Bischoff had Holz, his chief engineer, take her up to periscope depth first. Bischoff scanned the horizon meticulously. Satisfied that they were perfectly alone, he had Holz bring her to the surface. They fired up the diesels and pointed the boat east. Their mission was finished, their boat was damaged, it was time to go home.

Two hours later a flying boat bellied down through the cloud layer and dropped a skinny black egg on them. Bischoff was up on the bridge, enjoying some fresh air, and had the presence of mind to scream some thing about evasive action into the speaking tube. Metzger, the helms man, instantly took it hard to starboard. The bomb plunged into the water exactly where the deck of U-691 would have been.

It continued in that vein until they got far away from land. When they finally limped back to their base at Lorient, Bischoff told this story to his superiors in tones of superstitious awe, when they finally broke the news to him that the enemy had this new thing called radar.

Bischoff studied it and read the intelligence reports: the Allies were even putting the shit on airplanes now! It could see your periscope!

His U-boat is no longer a rat in a dark cellar. Now it is a wingless horsefly dragging itself across an immaculate tablecloth in the streaming light of the afternoon sun.