> They would also bring up proof, usually something that could be tied to the vessel, which could be a piece of military-grade equipment or even silverware engraved with the names of the ship or the enemy seal.

I believe traditionally, a diver will bring up a ship's bell for this purpose, if they are able. But maybe I'm off base about about, particularly when it comes to an enemy ship.

https://en.wikipedia.org/wiki/Ship%27s_bell

https://qr.ae/p26Ha0

https://www.washingtonpost.com/history/2024/02/20/bell-ship-....

Super cool

My grandfather was a submariner in the Pacific during the war, they were even inside Tokyo bay during wartime. He had many stories, one of them was that the batteries always got the priority in regards to water. Especially on patrol and missions, they would often go days between wiping themselves down with hand towels from a basin of shared water, all to preserve the fresh water for the batteries.

He was on the Saury

Do subs not have a sensor at the top that's able to detect things like ships right above them?

Those Saturn Vs are so amazing.

Everything I think about them. As you state, just the fuel pumps (that pump fuel at cryo temperatures) are hundreds if thousands of horsepower and are amazing fears of engineering on their own. Each piece of that engine is like that.

I had the immense privilege of seeing a few F1s in person recently in DC and I was not let down.

Thank you for bringing them up.

According to Wikipedia for USS Virginia class subs, the propulsion is 1 × S9G nuclear reactor280,000 hp (210 MW).

Good catch, I remember someone referring to a sub that way and never double checked the numbers.

right, horsepower not hit points I see now.

Those are usually different divers, sent as detachments to certain boats only for special missions. They are trained in using closed-circuit gear and perhaps in saturation operations, and aren't part of the submarine's standing crew.

The sub's standing crew would typically have a few qualified divers trained in just the basics. They would only use open-circuit gear on shallow bounce dives for inspections and light maintenance. Anything more complex would require bringing in a dedicated dive team.

They've even been alleged to "maintain" pipelines.

Generally it’s just various design parameters. Until the newest (and not-yet-built) Columbia-class, boats are all steam propulsion, and you can hit various pressure limits for components without maxing the reactor out. That said, yes, with nominal conditions generally All Ahead Flank will have the reactor output at 100%. All Back Emergency usually hits some other limit first.

Columbia-class is electric drive, which is absolutely wild to me. Those are monstrous motors.

Source: I ran a reactor on a Virginia-class (not USS Virginia, the subject of the article, but in the same class).

From first principles I'd expect the functional limit not to be one of power generation but of energy transfer. The limit probably manifests as wiring and motors overheating in a full electric drive (I don't think any subs are...) or as sound, heat and fatigue in reduction gears and gear shafts.

'Net' is a generic term. I have a 'computer', NOAA has a 'computer', but they aren't the same thing. I would be surprised if a fishing net was sufficient to stop a military sub.

Also, subs now are a lot more capable than they were then.

They are in actively using, where convenient to block large water area. As even in war ports, usually active traffic.

Second reason why now limited usage, WWII submarines was very limited power, many experts consider them as just high-speed boats with extremely limited underwater capabilities, but modern submarines are really powerful, especially nuclear.

Modern nuclear subs turn the prop with hundreds of thousands of horsepower. That is very hard to stop.

Here's a modern commercial fishing net: [1] The net itself isn't that heavy per unit area; it's just big. The top support line of the net is a string of floats, like pool lane markers, but larger. They're fishing for herring, not the Great White Whale.

Anti-submarine nets are far, far heavier.[2]

MESH ROPES: - flexible steel galvanized wire rope

This is a single strand, flexible steel galvanized wire rope consisting of 70 wires and 21 hemp yarns. It is one-inch in diameter, has a breaking strength of 98,280 pounds and is internally lubricated and protected against the action of salt water by saturating the fiber cores with a preservative composition. It weighs 1.8 pounds per running foot and is supplied on reels carrying 3,000 feet of wire and weighing 5,000 pounds packed for shipment.

The top support line of a submarine net looks like a bridge cable. The floats are the size of cars or larger.

[1] https://www.youtube.com/watch?v=k_CP6VtgDVc

[2] https://maritime.org/doc/netsandbooms/index.php

For safety, you do not want it to stop the sub. You want the sub to tear right through it or else the sub is going to take your boat with it, and what if the sub decides to dive?

I understand how this works, but for some reason, when I read your comment, I thought of Flappy Bird.

> As a civilian I’m in no position to critique the CO’s decision making.

To nitpick, you absolutely are. The military reports to the civilians; that is who they are accountable to.

That said, I don't know anything about submarines. But it has nothing to do with being a civilian or military. It's the trick of management, oversight, responsibility - we need to oversee and make responsible decisions for things where we lack expertise. I need to hire a plumber even if I know nothing about plumbing. Other people need to hire IT professionals, and IME some of them know nothing about IT!

> Not hard to notice the net on the sonar or passive listening devices surely.

Are you saying that because you know that the net makes noise?