He would paint the sea bottom with their blood. He would remain at sea until the food was gone, and beyond, until the last Nagasaki had been launched and had hit its mark. Then he would sail only for the rendezvous with the Chrysanthemum, reloading torpedoes, food and bottled water. He would give the crew and his officers twenty-four hours with the replenishment ship’s prostitutes, comfort women, and they would be back ready for battle. The thought of indulging himself with a comfort woman did not cross his mind. He could only focus on one thing — righting a wrong. The lower console of the Second Captain was a text display of intercepted radio messages from the Americans, with some probable decodings. They weren’t assured of being correct. Many times the names for things came through but numbers were problems. Typically numbers, such as the latitudes and longitudes of positions, were double or triple encrypted. The first encryption was electronic, converting the raw-form message into meaningless electronic symbols that were then sent over the radio circuits. A second encryption could be done with the radio transmission itself, in which several dummy messages could be transmitted at once on separate frequencies, the real message cut into the text of the various dummy messages so that the actual radio transmission jumped frequencies, the receiver on the other end decoding all half-dozen messages and discarding the portions of the dummy messages that had no meaning, retaining only the vitals of the actual message. Even then a third encryption could be done at the point of receipt, where numbers that came out of the system were altered by the message reader. A one could become a three, a four a six, with a constant added on or multiplied with the “raw” number. Sometimes numbers were subtracted. Sometimes they were inverted and the nearest whole number used, sometimes multiplied by pi, then the third decimal figure the result of the convolution. This could go on to the point of absurdity, but in any case there had been so many cases of latitude and longitude distortion from messages that were broken that Tanaka no longer trusted them. It was the verbal content of the messages that intrigued him. The term “wolfpack” recurred several times. Tanaka reclined in his seat, recalling the rich history of submarines, when in the last great war the Nazi submarines would gather together to attack convoys. If one was too far away, the other boats might be better positioned — the old vintage boats too slow to chase a swift convoy, relying instead on positioning themselves in the paths of the surface ships. In addition to positioning, two boats had twice the torpedo loadout of one. Finally, if one were to come under attack, a second boat could vector in and counterattack out of nowhere. There was one case that came to mind when the destroyer Aggressive was closing in on the damaged German Untersee-boot U-458 to ram and sink her, and the undetected U-501 was submerged at a right angle to Aggressive’ assault, delivering three torpedoes to the attacking destroyer, breaking her in half and sinking her just a few hundred meters before she would have overrun the U-458. Both U-boats had escaped. So now the Americans were going to gang up for safety from the aggressions of the Destiny class.
Tanaka tapped through some sequences, coaxing the Second Captain to extrapolate the positions of the Winged Serpents sister ships, the Destiny IIs. The Three-class ships were virtually useless in a fight with a submerged enemy. Most of them were probably already sunk, dead and gone, their poor programming inadequate to the task of fighting a true antisubmarine-warfare attack-submarine. But the Two-class ships would be there patrolling the waters surrounding the Home Islands, preparing themselves with the same intelligence data that he had. He considered putting up a message to the other ships in his Two-class squadron but decided against it. The commanders knew what they were doing. Tanaka closed out the lower display and dialed in the sonar computer-screened data, the computer looking for preset characteristics, filtering the ocean’s noise through the system’s knowledge of what the American submarines sounded like. The raw data coming in from the sea was voluminous and random, but a man-made ship made pure tones, tonals and specific transient rattles. Bangs and flow noises and squeaks. The computer could be used to filter out the meaningless clutter of the seas and look only for noises that matched pure tonals, the regularity of a screw thrashing through the seas, the noise of a hatch slamming, a sewage pump putting water overboard, a torpedo tube flooding. The Two class’ Second Captain combat control system had catalogued over ten to the fifth transient and tonal noises, and although that sounded like a lot it was a thousandth of a percent of the random noise of the sea.
