Welcome back everyone to My Weird Prompts. I am Corn, and we have reached a pretty significant milestone today. This is episode seven hundred fifty. It is hard to believe we have been at this for so long, but here we are, still digging into the strange and the complex. Seven hundred fifty times we have sat in these chairs and tried to make sense of the world.
Herman Poppleberry here. Seven hundred fifty episodes, Corn. That is a lot of hours of us talking. I think our regular listeners probably know my coffee preferences and my sleep schedule by now. They definitely know my feelings on mechanical keyboards and archival paper. But honestly, there is still so much out there to explore. The world does not stop being weird just because we have talked about it seven hundred fifty times. If anything, the more we look, the weirder it gets.
Very true. And today, we are diving into something literally deep. Daniel's prompt for this episode is about the tactical world of submarines. He is interested in why they remain such a critical part of naval fleets, how they navigate without Global Positioning Systems, and how they stay hidden from even the most dedicated civilian tracking communities. It is a world of shadows, silence, and some of the most intense physics on the planet.
This is a fantastic topic. Submarines are essentially the ultimate masters of the shell game. While a surface fleet is a massive, visible display of power—think of a carrier strike group as a floating city that screams "I am here"—a submarine is a silent, invisible threat that changes the entire calculus of a conflict just by potentially being there. The psychology of undersea warfare is just as fascinating as the physics of it. It is about the "known unknown."
It really is. And Daniel mentioned something in his prompt that I want to start with. He brought up the idea of speed and whether submarines have a speed advantage over surface vessels. I think there is a common misconception there. People see these sleek, cylindrical shapes and think they must be the Ferraris of the ocean. They look like they should just slice through the water at incredible speeds.
Right, and it is actually quite the opposite in many cases. If you look at the physics, water is about eight hundred times denser than air. When a ship is on the surface, it is dealing with wave-making resistance. As a ship moves, it creates a bow wave. To go faster, it essentially has to climb over its own wave, which is a huge energy sink. But a submarine, once it is fully submerged, does not have to deal with waves. However, it is entirely encased in a high-viscosity fluid. It has a massive amount of surface area creating skin friction.
So, even with those nuclear reactors putting out insane amounts of power, they are not necessarily outrunning a fast destroyer?
Generally, no. Most modern nuclear-powered attack submarines, like the Virginia-class or the British Astute-class, have a top speed somewhere in the range of twenty-five to thirty-five knots. Some older Soviet designs like the Alfa class could hit forty knots because they used liquid metal cooled reactors and titanium hulls, but they were incredibly loud at those speeds. They sounded like a freight train underwater. Compare that to a modern surface combatant or even a high-speed ferry, and the sub is not winning a drag race. The real tactical advantage of a submarine is not speed, it is sea denial through stealth.
Sea denial. That is a term we see a lot in naval strategy. Can you break down what that actually means in practice? Because it sounds a bit abstract.
Sure. Think of it this way: Sea control is when you want to use the ocean for your own purposes, like moving cargo or launching planes from a carrier. You want the ocean to be a safe highway. Sea denial is simply making sure the enemy cannot use the ocean. You do not need a hundred ships to do that. You just need the enemy to believe there might be one submarine lurking in a million square miles of water. It forces them to spend an enormous amount of resources on anti-submarine warfare, or A S W. They have to move slower, use zig-zag patterns, and deploy dozens of helicopters and sonar buoys. The mere existence of a submarine fleet creates a massive tax on every move the enemy makes.
It is like a psychological "area of effect" weapon. A single submarine can tie up an entire carrier group just by being "possibly present." But for that to work, they have to stay hidden. Daniel asked about the stealth aspect, specifically how they remain untrackable by civilians. We live in an age where you can track almost every plane in the sky using A D S B Exchange and every cargo ship on the ocean using apps on your phone. Why doesn't that work for submarines?
It comes down to the Automatic Identification System, or A I S. By international law, most large commercial vessels are required to broadcast their position, speed, and heading via A I S transponders. This is for collision avoidance and search and rescue. Civilian tracking sites like Marine Traffic or Vessel Finder just aggregate those broadcasts. Military vessels, however, have the legal right to turn those transponders off for national security reasons.
Right, so they just go dark. But surely with modern satellite imagery, someone could spot them? We have companies like Planet Labs taking photos of the whole Earth every day.
You would think so, but the ocean is unimaginably vast. Even with high-resolution satellites, you are looking for a needle in a haystack that is painted dark blue or black and is often underwater. Once a submarine dives, it is essentially gone from the visual spectrum. Light does not penetrate very far into the ocean. Blue-green light goes the deepest, but even then, after a few hundred meters, it is pitch black. A satellite looking down sees nothing but the surface. Now, there is Synthetic Aperture Radar, or S A R, which can see through clouds and at night, and it can sometimes detect the "wake" or the surface disturbance a submarine makes even when it is submerged, but that requires knowing exactly where to look and having the satellite pass over at the exact right moment.
So the only way to find them reliably is through sound.
Exactly. Under the water, acoustic energy is king. This is where the real tech war happens. Modern submarines are covered in anechoic tiles. These are rubbery coatings, often made of polyurethane or synthetic rubber, that do two things. First, they absorb the incoming pings from an enemy's active sonar, so the sound does not bounce back as a strong echo. It is like covering a room in foam to stop an echo. Second, they dampen the noise coming from inside the submarine itself, like the hum of pumps, the vibrations of the engine, or even the sound of a wrench dropping on a deck plate.
I remember reading about the transition from traditional diesel-electric subs to what Daniel mentioned, Air Independent Propulsion, or A I P. How does that fit into the stealth equation? Because for a long time, the "diesel" part was the weak link, right?
That is a huge development for non-nuclear navies. Historically, a diesel-electric sub had to surface or use a snorkel every day or two to run its engines and recharge its batteries. That made them vulnerable because a snorkel can be spotted by radar. Nuclear subs solved this because they do not need oxygen for their power source, so they can stay down for months—basically until the food runs out. But nuclear reactors are noisy. You have to constantly run coolant pumps to keep the reactor from melting down, and those pumps make a mechanical noise that can be detected.
So a nuclear sub is never truly silent?
It is very quiet, but there is always a baseline mechanical hum. A I P systems, like fuel cells or Stirling engines, allow a conventional submarine to stay submerged for weeks without a nuclear reactor. When they are running on batteries or fuel cells, they are almost perfectly silent. There are no massive moving parts, no coolant pumps. In some scenarios, a modern A I P submarine, like the German Type two hundred twelve, is actually harder to detect than a massive nuclear-powered boat. They are the "black holes" of the ocean.
That is fascinating. It is almost like the smaller, more agile tech is catching up in specific niches. But let's get to the part of Daniel's prompt that really intrigued me: navigation. If you are a thousand feet underwater, you cannot see the stars, and GPS signals, which are high-frequency radio waves, cannot penetrate more than a few inches of salt water. How do you know where you are? You can't just roll down the window and look for a landmark.
This is where we get into the heavy lifting of Inertial Navigation Systems, or I N S. Daniel made a great analogy in his audio prompt about walking across a dark room. If you know exactly where you started, and you can measure every single step and every turn you take with perfect accuracy, you can figure out where you are without seeing anything. This is called "dead reckoning," but on a much more sophisticated level.
But in a submarine, you aren't just taking steps. You are dealing with ocean currents that might be pushing you sideways, changes in water density that affect your buoyancy, and the fact that you are moving in three dimensions. How does the I N S handle that?
It uses a suite of incredibly precise sensors. You have accelerometers to measure changes in velocity along three axes and gyroscopes to measure changes in orientation—pitch, roll, and yaw. Modern subs use Ring Laser Gyros or Fiber Optic Gyros. These do not have spinning mechanical parts like the old-school gyroscopes you might have played with as a kid. They use the Sagnac effect.
The Sagnac effect? That sounds like something I should have learned in high school physics but definitely didn't.
It is brilliant. You send two beams of laser light in opposite directions around a closed loop of fiber optic cable. If the loop is stationary, the two beams will arrive back at the starting point at the exact same time. But if the loop rotates—because the submarine is turning—one beam has a slightly shorter path to travel than the other. By measuring the interference pattern between those two beams of light, you can detect even the tiniest rotation. We are talking about measuring rotations that are smaller than the width of a human hair over several miles.
Daniel asked a very specific question about the reliability of I N S in a sub versus an airplane or a ballistic missile. That seems like an important distinction. Why can't we just use the same unit for all three?
It is a brilliant question because the requirements are totally different. Think about a ballistic missile, like a Minuteman three or a Trident two. It only needs its I N S to be accurate for maybe twenty or thirty minutes. It is moving at incredible speeds, thousands of miles per hour. Any small error in the sensors gets magnified quickly because of that speed, but because the flight time is so short, the "drift" does not have time to become catastrophic before the missile hits its target.
And an airplane?
An airplane is usually only in the air for a few hours, and it can constantly reset its I N S using GPS or ground-based radio beacons. It has "external truth" it can check against. But a submarine? A submarine might stay submerged for weeks or even months. It has no "external truth" unless it risks coming to the surface.
So the drift problem must be immense.
It is. In the world of I N S, "drift" is the enemy. Even if your sensors are ninety-nine point nine nine percent accurate, that tiny error accumulates over time. If a submarine's position drifts by just a few meters every hour, after a month at sea, they could be miles off their actual position. This is why submarine I N S units are some of the most expensive and precise pieces of machinery ever built. They are orders of magnitude more stable than what you would find in a missile. They use things like Electrostatically Supported Gyros, where a beryllium sphere is suspended in a vacuum by electric fields to eliminate friction.
But surely they have to "zero out" the error eventually, right? They can't just guess for three months and hope they don't hit a continent.
Right. They use what is called "position fixing." Occasionally, the sub will come to periscope depth and raise a small mast to grab a quick GPS fix. That takes just a few seconds. They update their coordinates and then dive back down. But in a high-threat environment, they might not want to do that because even a small mast can be spotted by radar or satellites. It is like a turtle sticking its head out of the water—it is the moment of greatest vulnerability.
So what are the alternatives? Are there ways to navigate underwater without surfacing at all?
There are, and they are quite clever. One method is bottom-contour navigation. The submarine has detailed digital maps of the ocean floor—the bathymetry. They use a very narrow-beam sonar to measure the depth and the shape of the terrain beneath them. By matching what they see with their maps, they can figure out exactly where they are. It is like a hiker using a topographic map to find their position based on the peaks and valleys around them, except the hiker is blind and using a cane.
That sounds risky, though. Using active sonar is like turning on a flashlight in a dark room. Doesn't that give away your position to anyone listening?
It can. That is why they use it very sparingly or use high-frequency, low-probability-of-intercept sonar. There is also gravity-map navigation, which is even more stealthy. The Earth's gravity isn't perfectly uniform; it varies based on the density of the crust and the underwater mountains. If you have a sensitive enough gravimeter, you can navigate by following the "gravity landscape" of the ocean floor. That is completely passive. No sound, no radio waves, just measuring the subtle pull of the Earth.
That is incredible. Navigating by the subtle tug of gravity because you are too hidden to use the satellites in the sky. It really highlights the extreme lengths we go to for stealth. It is a very high-stakes game of hide and seek.
It really does. And it brings us back to Daniel's point about why these are still relevant. In a world of total surveillance, where every square inch of the surface is being watched by someone, the submarine is the only asset that offers true uncertainty. If you are a military planner, you can look at a satellite feed and see exactly where an enemy's tanks are, where their aircraft carriers are, and where their missile silos are. But you cannot know for sure where their submarines are. They are the "wild card" in the deck.
And that leads into the most sobering part of their role: the nuclear deterrent. We have talked about this in previous episodes, like when we discussed second-strike capability. The idea is that even if a country is hit by a surprise nuclear attack that destroys all its land-based missiles and airfields, its submarines are still out there, hidden in the deep, ready to retaliate. It is the foundation of Mutually Assured Destruction.
Exactly. It is the ultimate insurance policy. As long as a country has a few ballistic missile submarines, or "boomers," at sea, a "total victory" for an aggressor is impossible. This is why countries like the United States, Russia, China, France, the United Kingdom, and as Daniel mentioned, Israel, put so much effort into their submarine fleets. It is not just about sinking other ships; it is about maintaining a balance of power through the threat of an invisible, unstoppable response.
Daniel mentioned the Dolphin-class submarines in Israel's fleet. From what I understand, those are quite unique because they are conventional diesel-electric boats, but they are widely believed to carry nuclear-capable cruise missiles. That is a different approach than the massive, hundred-and-seventy-meter-long Ohio-class subs the U S uses.
It is a very specific tactical solution. Israel's geography is small, so they do not need the massive, long-range endurance of a nuclear sub that stays at sea for six months and travels ten thousand miles. They need something that can lurk in the Mediterranean or the Red Sea, stay very quiet using that A I P technology we talked about, and provide that second-strike guarantee. It is a "boutique" submarine force, highly specialized for their specific neighborhood. The Dolphin-class is actually based on the German Type two hundred nine design, but heavily modified.
It is interesting how the technology scales. You have these underwater cities, and then you have these sixty-meter boats that are arguably just as strategically important. But let's talk about the "hunters." If submarines are so hard to find, how do you actually hunt one?
It is a process of elimination. You use "passive sonar" first, which is just listening. You have highly trained sonar technicians who spend their entire lives learning to distinguish the sound of a Russian Akula-class propeller from the sound of a blue whale or a cargo ship's engine. They look at "waterfalls" on their screens—visual representations of sound frequencies. They are looking for "transients"—a door slamming, a pump turning on, or the "blade rate" of a propeller.
And if they hear something?
Then they might use "active sonar," which is the classic "ping" you hear in movies. But that is a last resort because it tells the submarine exactly where you are. Modern A S W also uses "magnetic anomaly detectors," or M A D. A large metal submarine distorts the Earth's magnetic field slightly. Planes like the P-eight Poseidon fly low over the water with a long boom on the back to detect these tiny magnetic shifts. But even that only works if the sub is relatively shallow.
And the technology is only getting more complex. One of the things that is changing the game right now, in early twenty-six, is the rise of Unmanned Underwater Vehicles, or U U V s. Think of them as underwater drones.
This is the next frontier. A large submarine can now act as a "mothership," releasing dozens of these small drones to scout ahead, lay mines, or act as decoys. Some of these U U V s, like the Boeing Orca, are huge—the size of a school bus—and can stay at sea for months autonomously. They can sit on the ocean floor and just wait for an enemy to pass by.
That must make the job of the hunters even harder. If you pick up a sound on your sonar, you don't know if it is a two-billion-dollar submarine or a fifty-thousand-dollar drone designed to sound like one. It is a hall of mirrors.
Precisely. The ocean is already a very noisy place. You have whales singing, underwater earthquakes, massive shipping traffic, and even "snapping shrimp" that make clicking noises loud enough to interfere with sonar. Trying to find a modern, silent submarine in that acoustic mess is like trying to hear a specific person whisper in the middle of a sold-out football stadium while everyone else is screaming and the band is playing.
You know, we have been talking about the high-tech military side, but I want to go back to the civilian tracking part for a second. Daniel noted that civilians can't track them. But there are these communities of "ship spotters" who hang out near naval bases like Norfolk in Virginia or Faslane in Scotland. They take photos of subs as they surface or leave port. Is that a real threat to their stealth?
It is a nuisance, for sure. Navies hate it. It is what we call O S I N T, or Open Source Intelligence. If a hobbyist posts a photo of a submarine leaving port at ten a m on a Tuesday, an adversary now has a starting point. If they know the sub's top speed, they can draw a circle on the map showing everywhere that sub could possibly be twenty-four hours later. It narrows the search area from "the whole ocean" to a specific region. That is why you often see submarines departing under the cover of darkness or in bad weather. Some navies even use "spoofing" where they have a different ship broadcast the A I S signal of a submarine to create a false trail.
I have even heard of cases where A I S data showed a naval vessel docked in one port while it was actually hundreds of miles away. Digital deception.
Oh, absolutely. There was a famous incident where A I S data showed a British destroyer and a Dutch frigate sailing right up to a Russian naval base in Crimea, but they were actually docked in Odessa at the time. Someone had spoofed the GPS coordinates in the A I S system. But for a submarine, the best deception is just silence. If you do not broadcast, and you do not surface, you do not exist to the civilian world. You are a ghost.
It is a strange existence for the crews, too. We should probably mention the human element. You are in a pressurized metal tube, no sunlight, recycled air, and you are navigating by math and gravity. You don't see the sun for months.
It takes a very specific type of person. Submariners are known for being some of the most technically proficient and mentally resilient people in any military. There is no "getting away" from your coworkers. You are "hot bunking" in many cases, where three people share two bunks in shifts. You have to be comfortable with the idea that your life depends entirely on the integrity of a few inches of steel and the accuracy of those Inertial Navigation Systems we talked about. If the I N S fails and you think you are in deep water but you are actually approaching an underwater mountain... well, that is how disasters happen.
There was that incident with the U S S San Francisco back in two thousand five, right? They hit an uncharted undersea mountain at full speed.
Yes, and that is a perfect example of why navigation is so critical. The mountain wasn't on their charts. Their I N S was working perfectly, telling them exactly where they were, but their "map" was incomplete. It just goes to show that even with the most advanced sensors in the world, the ocean is still a frontier that we haven't fully mapped. We actually have better maps of the surface of Mars or the Moon than we do of the deep ocean floor. We have only mapped about twenty-five percent of the seabed to high resolution.
That is a staggering thought. We are sending nuclear-powered machines into a landscape that is less understood than another planet. It really puts the "weird" in "My Weird Prompts."
It is the last great wilderness on Earth. And that is why the submarine remains the ultimate tactical asset. It thrives in that unknown. While the rest of the world is becoming more transparent, more tracked, and more connected, the deep ocean remains opaque. As long as that is true, the submarine will be the most feared vessel in any fleet. It is the only thing that can truly disappear.
So, to summarize for Daniel's prompt: the tactical advantage is stealth and the ability to deny the enemy the use of the sea through uncertainty. They navigate using incredibly precise Inertial Navigation Systems—Ring Laser Gyros and accelerometers—that are designed to resist drift for weeks at a time, unlike the short-term systems in missiles. And they stay hidden from civilians simply by not participating in the digital systems that track the rest of the world, and by being physically invisible to almost everything except the most advanced sonar.
Spot on. And for those interested in the navigation side, keep an eye on quantum sensing. There is research into cold-atom interferometry that could lead to I N S units that basically never drift. They measure the movement of atoms cooled to near absolute zero. If that happens, submarines could stay down even longer without ever needing a GPS fix. They would be truly independent of the surface world.
The tech just keeps moving forward. Well, this has been a great deep dive, literally. Herman, thanks for the expertise. I feel like I need to go stand in the sun for a bit after talking about months underwater.
Always a pleasure, Corn. I could talk about gyroscopes and the Sagnac effect all day, but I think we have covered the essentials for Daniel. It is a world of silent professionals and incredible math.
Before we wrap up, I want to say a huge thank you to everyone who has been with us for these seven hundred fifty episodes. Whether you started with episode one or you just joined us today, we really appreciate you spending your time with us. It is your prompts that keep this show going.
We really do. And if you have been enjoying My Weird Prompts, please take a moment to leave us a review on your podcast app or a rating on Spotify. It sounds like a small thing, but it genuinely helps other people find the show and keeps us in the algorithms.
You can find all our past episodes, including our deep dives into nuclear strategy, maritime history, and even that weird episode on the physics of bubbles, at myweirdprompts dot com. We have got an R S S feed there for subscribers and a contact form if you want to get in touch. You can also reach us directly at show at myweirdprompts dot com.
We are available on Spotify, Apple Podcasts, and pretty much everywhere you listen to podcasts. Thanks again to Daniel for the prompt that sent us down this undersea rabbit hole. Keep those prompts coming!
This has been My Weird Prompts. We will see you next time for episode seven hundred fifty-one.
Goodbye, everyone. Stay weird.
