The inner hull contracts as the pressure increases. The [[sound]] is unnerving, but you are well above [[crush depth]].
You should check the [[sonar]].400 meters. One could probably dive beyond that, but not without risking a catastrophic [[hull breach]].It's best not to [[think about it]]. It's not a concern at this [[depth]].A knocking. Nuts and bolts settling into what will comfortably support the construction at this [[depth]].Without the instruments, it would hard to tell. 200 meters according to the gauge. They're the only point of reference. At this depth, the vessel is unlikely to end up as a blip on a [[bogey]]'s sonar, and certainly out of reach of surface radar. Blown cover in these waters might end up being a "[[geopolitical disaster->geo-political disaster]]."The crush depth is a minimum rating. Chances are that the [[ball of metal->submarine class]] could dive much deeper before the hull collapses. It is not a concern at this [[depth]], though. You feel a pearl of sweat reach your brow. You really should check the [[sonar]].[[Armed->armed]] submarines don't officially have any business here. Both sides of the conflict somehow end up sending armed submarines to make sure that the enemy respects this agreement. This shared hypocrisy is instrumental to maintaining the balance of power.You haven't ever seen one. Well, heard, really. It's hard to [[stay prepared]] for something that never happens.You are to avoid confrontation at any cost. The enemy is expected to operate under similar circumstances. Recon. You are [[armed]], though.Three wire-guided torpedoes. That's all this [[class of submarine->submarine class]] will carry.Nothing, passively. One sweep is the most you feel like risking. The [[button]] flickers.The sonar rings. It's mostly a flat line, but an echo suggests something 150 meters astarboard. You'd have guessed that it's a [[topographical feature]], but not here. Time to check the [[ship charts->charts]].The signature doesn't match any of the ships in the binder. Another [[ping]] might be worth the risk, but if it's heading this way, it will eventually end up on [[passive sonar->passively]] as it approaches.Another sweep. Whatever is causing the echo is closer now, heading towards the ship. 100 meters. Has it discovered you? It's best to [[stand by]].Turning the generators off, waiting for a sign. Nothing. Every creak the ship makes could compromise your position. It could be an [[animal]]. Sweating profusely, you are considering the risks of another [[ping]].Whales mostly. Usually not at this depth, but it's not unheard of. For a minute it seems like the most plausible explanation. An animal wouldn't mind another [[ping]].One-person scout. It's basically a metal ball with a periscope, a set of propellers and three torpedo tubes. It's very cramped and lonely. Captains of this type of vessel have to go through extensive psychological testing before each mission. Paranoia is a great way to deal with the monotony. You'd better check that [[sonar]] now.Time passes. At its initial rate and direction, the echo ought to be 50 meters away. There is no hint on the passive sonar until the ship suddenly shifts violently. The [[bilge water]] splashes below your seat. The chains holding the footlocker in place stretch as it slides across the floor. The trim is still off when you [[restart the generators]].Flick three switches and the propellers start spinning, targeting [[15 knots]]. The thing that just moved past the ship would already be aware of your presence, so you initiate another [[sweep]].You set the sonar up for continuous sweeps. The echo is much wider and greater in amplitude now, astern. It's definitely an [[animal->animal2]]. You're soaked with sweat. The generator runs warm, and the tiny compartment reserved for the lone captain feels more cramped than ever. [[Surfacing]] would be a huge risk, definitely a breach of protocol, but the alternative seems more [[attractive]] now than ever.The ceiling light reflect in its motion through the well grating as it sploshes from side to side. Better [[leave->restart the generators]].Not a whale. A whale would not have stayed at this depth for this long. An unnerving [[sound->sound2]] seems to confirm this.These are neutral waters, but with the well understood mutual presence here, it seems like your discovery would at worst be propaganda fodder. It somehow seems inconsequential compared to whatever just casually pushed the vessel aside in passing.
Staying put and watching the [[sonar->angle]] closely is the best course of action.More like a ship horn than any animal you've ever heard. A blaring, monotonous burst that lasts for more than a couple of seconds before ending abruptly. With each sweep of the sonar, the echo ends up at a different [[angle]].It's following the ship closely. A quick glance at the [[ballast blow]] switch through its glass cover.There is a reason you'd have to break a glass pane to flip it. Compressed air would be released to push the water out of the tanks, and the systems on board would have a hard time fully compensating for the resulting decompression.
It's best not to. At this point, there is no real evidence of hostile intent anyway. The echo is to the port side now. The vessel has reached its target velocity. You adjust the trim for ascension, hopefully causing the creature to [[lose interest]].It doesn't. Two loud bangs on the port side of the hull. It's creaking under what seems like immense pressure. One of the propellers stop, causing a jarring noise from the shaft. [[Panicking]], you bring the propellers to a halt and decide to [[load a torpedo]].The pull of a lever forces the torpedo into the launching tube. Two lights start blinking. Turning a wheel opens its the valve, while you notice the depth gauge. It's pulling downwards. [[One light left]].You arm the torpedo which simultaneously releases the spool brake. The hull moans. Ready to [[fire]].You launch the torpedo. The spool starts spinning loudly. No chance of hitting the animal, it proves to be a [[distraction]]. Now is the time to [[blow the ballast]].It has released the hull to pursue the torpedo. [[Blow the ballast->blow the ballast]]!You cut the torpedo wire, break the glass and pull the switch. The supply of compressed air is thankfully generous. The sound seems to have regained the attention of the creature, which is yet again [[closing in]] on the vessel.50 meters. There is not much else you can do to escape it. The depth gauge moves steadily as the now fully buoyant vessel ascends. The hull emits a familiar sound as the pressure decreases. No option but to [[wait this out->wait it out]].The animal is here. It grabs onto the ship again, rattling it as the ascension halts suddenly. You can hear the outer hull buckle. A caged red lamp lights up. There's a breach. Not yet seeing where, you [[connect the bilge pump]].The pump starts whirring. Another leak as the hull screams in the grip. The water pours down. You look down the bilge well, but it's not emptying. Depth is increasing. Your only chance now is to [[call mayday]].Again a breach of protocol, considering the temporary national embarassment it would cause. You [[release the radio buoy]].Without the hammering of the creature, you'd hear another spool start whirring as you release it. At least, that's what you hope, now standing in bilge water. Another look at the depth gauge. [[350 meters]].Water is rushing in, knee deep now. A new slight echo is visible through the noise on the sonar display, seemingly a [[static feature]] nearby. By now, the radio buoy should have reached the surface. Time to call [[mayday]].It's near. There is a chance that [[firing at it]] would scare the creature away. At this depth, there is also a chance that the stress of the explosion would crush the ship. You're knee deep in water. There is no other option.Before there's a chance to finish typing the message, there is another loud crack as water starts spraying in from the side. You fall down, the ship shaking. The creature practically bends the hull open and you drown.
The EndYou load the next torpedo, open the valve and arm. You flip the switch and barely grab the railing before the explosion rolls the submarine to the side. The creature releases the ship, and the depth gauge starts moving counterclockwise again. It will not stay buoyant for long, but the exact math escapes you.
The EndFully submerged, the modest engine can't give much more. The advantage of the small vessel lies in its relative insignificance on [[sonar->sweep]].The smell of sea water. Seagulls. Things people don't really know how much they could possibly long for until they've been submerged for more than a few days. You have a hard time fighting the urge to [[surface->Surfacing]].Most of the training amounted to avoiding it, but the difference between panic and the correct course of action blurs during [[confrontation->load a torpedo]].The depths are not abyssal, but still vast enough for safe passage even without sonar. Better [[check the charts->charts]].