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“These areas are far from the major shipping lanes,” said the navigator, looking down at the floor, avoiding eye contact. “And far from the normal Trident operating areas. They don’t get updated as frequently, and these areas aren’t surveyed like our normal waters.”

Jabo nodded; it made sense. Some of their normal operating areas were surveyed so well that they could fix their position within a few feet just by taking a series of soundings, measuring the water’s depth, determining the exact contour of the ocean floor and finding a match on the chart. Looking at a chart like the one in front of them could lull a watch officer into a false sense of security, as it appeared to describe a vast area of deep, featureless ocean.

“So at twenty-two knots, how deep do we need to be, Lieutenant Morrissey?” asked the Captain. Morrissey was on his second patrol, trying desperately to qualify OOD. The question the captain asked related to the ship’s “submerged operating envelope,” part of the bedrock of running the ship safely, and something every OOD was supposed to know so well that it became part of his intuition. Morrissey furrowed his brow in thought.

“Six hundred and eighty feet?” he said.

“Is that an answer or a question?” said the XO. “Grow some balls.”

“My answer.”

“Well you happen to be right. Now I’ll ask one of these smart ass OODs why that is. Lieutenant Kincaid?”

“Two things limit depth at that speed,” said Kincaid. “A stuck stern planes incident, and the threshold for cavitation.”

“Is that right, Morrissey?” said the XO.

“Yes sir.”

“So what’s this cavitation that Kincaid is so worried about?”

“The noise made by collapsing bubbles of water vapor in the low pressure area behind the ship’s propeller,” said Morrissey.

“Good job. At that speed we need to run pretty deep so that we don’t pop out of the water in an accident, and so that we don’t cavitate and make a lot of fucking noise so the bad guys know we’re coming.” He paused. “Which brings us to the second reason we are here. Danny, dim the lights.”

Suddenly intrigued, Jabo leaned back in his chair to hit the switch. The XO clicked a few keys on his laptop and projected a grainy image onto the movie screen pulled down at the front of the room. It was a black and white satellite photo of a two submarines at a pier, tied along side each other, head to tail. He instantly recognized it as a Soviet design, the long, blunt conning tower being distinctively Russian. It took him just a moment longer to identify the specific class.

“Anybody know what these are?” he asked.

“Russian,” said Jabo. “Kilo Class.” There was a murmur of admiration among the other JOs at Jabo’s acumen. The short squat body of the enemy boats and the somewhat blocky lines of the hull made them look at the same time primitive and yet seaworthy, as indeed they were. Kilos were one of oldest and largest classes of submarines made by the Russians and the Soviets before them.

“You’re sorta right, smart ass. They’re Soviet Kilos, but these particular boats belong to our friends the Red Chinese. Our friends in intel tell us that these are a particular version of the Kilo called a Project 636 boat. Jabo, do you know what that means?”

“They call it the ‘black hole,’” said Jabo. “Because it disappears from sonar.”

“Correct again. Running on its battery, it’s one of the quietest submarines in the world. We’ll have training on it tomorrow night in the wardroom after dinner. Danny, I think you just volunteered to give it. So study up tonight while you’re on the midwatch. Teach us what we need to know: max speed, sound signatures, armament, etcetera. Got it?”

“Aye, aye sir.”

The XO cleared his throat and turned to the captain. All were silent, waiting to hear why they suddenly needed to understand the specs of this particular Russian submarine.

“On the broadcast, about an hour ago, we received a message from SUBPAC saying that these two boats have departed the Chinese submarine base at Ning-bo. Heading for the open seas. Anybody want to guess what they’re doing?”

No one said anything.

“Me neither,” said the Captain. “But we’ve been reminded by SUBPAC, who has been reminded by the national command authority, about how important our mission is. And we’ve also been reminded that China considers the seas we are entering to be their sovereign, territorial waters. So if they were to identify an unknown submerged contact in those waters…let’s just say we’re not going to let that happen.”

For a moment they all just stared at the screen, absorbing the fact that the boats depicted in the grainy, aerial image were now their adversaries.

The captain continued. “We have to get to Suao in time, and we have to get there undetected. This is the mission we’ve been handed, and I intend to complete it successfully. So follow the navigator’s track, and memorize every angle of the submerged operating envelope. If we stay inside it then the best minds in the Navy assure us that we’ll remain undetected and safe. Be smart. Any questions?”