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Errata, Potential Mistakes, & Retcons

The boat shoulda sunk more quickly in the first chapter

There's a pretty strong argument to be made that in the first chapter, after being rammed, the Prospect would have been damaged so badly that it would have flooded quickly and sunk in a general atmosphere of emergency and alarm. A few readers have indicated to me that they believe a quick sinking would have been more realistic (and possibly that they would have preferred dramatic action like that to launch the rest of the book).

Let me lay out three reasons why the slow-leak sinking as I wrote it is at least plausibly realistic:

  1. The Prospect has huge saddle tanks on its sides that are its main ballast tanks. (See the details for the USS Tang (SS-563), on which the hull of the Prospect was loosely based.) Conceivably the saddle tanks could have / would have absorbed most of the energy of the ramming, and sustained significant damage — but that damage would have been outside the pressure hull, as the saddle tanks are. Some — but much less — damage could have resulted to the pressure hull yielding the leaking but not breached situation the Prospect faces in the first chapter. (Submarine pressure hulls were and still are made of the strongest steels known to material science.) The result is a badly damaged main ballast tank, and a modestly damaged pressure hull, that slowly lowers the boat into a position where it is unable to gain the surface.
  2. Real (war) submarines have many small compartments — which is what you want if you anticipate a situation where you might take damage (like war). Small compartments allow you to isolate leaks and repair them in the compartment. But a small leak in a small compartment will quickly fill the space with water — because there's simply not much space to fill. However on a cargo submarine, one could imagine designers assuming the boat would generally not be taking damage. And since the priority is space for cargo rather than weapons system, a single large compartment might be designed into the boat — as is the case in the Prospect. A leak in a small leak in a large compartment will take longer to make itself known.
  3. Real (war) submarines also have a crew complement of many dozens, at least — all those extra people are necessary for fighting a war boat. As a result, on a war sub, there are always a number of people throughout the boat, in most if not all compartments. The Prospect, being a cargo submarine, has a crew complement of half a dozen or so. Like a surface cargo vessel, there are many parts of the boat that would not generally have anyone passing through them on a regular basis. So another reason it might take a while to idenfiy a slow leak is there just isn't anyone around to see it.

Is this a retcon? Yes, it is. (Except, is it a 'retcon' if you are trying to retroactively correct a technical issue? Is this actually a 'retfix' or 'retmech' or 'rettech'?) The thing is, I wanted to open the book by stealing this bit of drama from many (many) Deadliest Catch episodes, and a few Patrick O'Brian stories, where it slowly dawns on a captain that the ship has a leak because they can feel how the extra water is affecting the handling of the boat. Then this is followed by a panic as the crew run around trying to figure out where the leak is coming from. I just love that slow-burn build-up to a desperate repair. The idea that this situation would be much less likely on a submarine than on a surface ship honestly had not occurred to me while I was writing. However, point number one above is pretty strong — if you can accept that the repairs to the saddle tank were carried out later "off-camera," as it were. (I think I forgot to address this at the depot — they actually needed divers to repair the saddle tank. This will be corrected if I do a 2nd edition at some point.)

The underwater docking bay should be pressurized, like an upside-down cup

If you have your middle-school science lessons burned into the back of your brain somewhere (I certainly do), then you might go into the depot section remembering the dry paper in the upside down cup submerged in a bucket of water, and so you might believe that the depot dock should be pressurized. However, this notion confuses saturation diving with submersibles/submarines. In saturation diving, people are put inside the upside down cup (diving bell, habitat, what have you). As the unit goes deeper, the pressure inside increases, potentially to the equivalent of many atmospheres. If you descend slowly enough, your body adapts to the pressure and then you can live at that pressure. The main result of this is you can have that sweetest element of underwater adventure stories: the moon pool! (See Sealab.) And, OK, maybe some people appreciate the technical merits of not need a massive steel pressure hull surrounding you when you are deep in the ocean. But trust me, if I could have crammed a moon pool into my book somewhere, it would be there.

Unfortunately, submarines don't work like that. They are kept at (more or less) one atmosphere of pressure, so the people inside don't have to go through compression and decompression processes. (As you can imagine, it's not always precisely the same pressure inside the sub as outside — things change while you're down there — so sometimes the hatch opens with a serious pop! But it's never a question of multiple atmospheres of pressure difference, just a slight mismatch.) But if the boat is at one atmosphere inside, and you opened a hole in a submarine (like a moon pool) when you were underwater, the water would flood in because the inside of the sub it at significantly less pressure than the ocean around it.

To get back to the underwater submarine dock: being about 30 meters down, if you pressurized it to match the surrounding water, it would be at about 3 atmospheres, compared to the 1 atmosphere of a docked sub. The sub wouldn't be able to open the hatch! Another more minor point, is that the depot wants to be able to maintain operations on the surface as well. If the depot were pressurized, it would require an airlock (and decompression process) to leave the depot on the surface.

So, at least until some physicist tears apart the specifics of my underwater dock scenario, the depot is correct in its mechanics.

Errata, February 8, 2024 version date