ASW and Convoy Warfare Today

[DWG]

Personal opinion but transits of cargo ships above 20knts is completely unrealistic.

MSC Daniela Class, 14,000TEU, 165,000DWT, Cruise Speed 23.5Kts
CSCL Globe Class, 19,100 TEU, 185,000DWT, Cruise Speed 20.5kts

There seem to be quite a few more large container ships and car carriers with speeds just under 20kts.

 

[Jimmo952]

Those container ships are not going to outrun cruise missiles, ballistic missiles and drones.

We are still going to need escorts.

The only questions are more what capabilities are nerded and what will the escorts will look like.

 

[johnpjones1775]

Only if the SSK is already in front of where the container ships are going.

If the 20kt ships are doing long zig-zags? Good luck getting in front of them. You're going to need a wolf-pack just to catch one merchie.



Do me a favor, see how long it takes to get ahead of a 20kt contact detected at 30nmi directly ahead of you. Assume that you can sprint at 35kts, and the contact is more-or-less paralleling your course. Your attack position needs to be at least 5nmi ahead of the target.

Side note: You need to get down to 700ft/200m or so to go that fast, so it'll take ~10min between sprints to pop back up to relocate the target.





Yes, that's a potential problem.

Except that a surface ship is also relatively limited in detection range versus a target. Better than a sub, since they have a helicopter and other comms. But still limited. (see my reply to JohnPaulJones1775)




Oops, they just zigged away while you were going fast and you lost them.




All radar does is slightly increase your visual detection bubble, and it has a higher chance of detection when a ship is superstructure down over the horizon versus the Mk1 eyeball. (for the non-sailors, when only the masts are visible above the horizon)




===========================
Remember, everyone, Merchant Hunting requires you to positively ID the target before you blast it.

Oh no! They zigzagged 5 miles East and 7 miles west slowing themselves down! How horrible. You have absolutely no clue what you’re talking about

 

[Scott Kenny]

Oh no! They zigzagged 5 miles East and 7 miles west slowing themselves down! How horrible. You have absolutely no clue what you’re talking about

How often did you hunt surface ships while you were in the Navy?

We did that a lot. Yes, as a missile submarine. Plus, my job was in control, either driving the boat or as part of Section Tracking Party when I wasn't driving. I've spent entire deployments doing this stuff because the Tactical Readiness Evaluation was at the end of the patrol.

You detect a contact at 30nmi. For argument's sake their course parallels yours at 20nmi range (just so that they're not 30nmi away from your course), placing them 15nmi behind your position on that parallel course (they're coming up behind you). For positive ID of the merchie target, you must get to within about 5nmi to see their national flag (merchies fly stupidly small flags).

You go deep and haul ass. Because you're not going to detect most skimmers below ~200ft due to the major thermocline, you lose contact as soon as you do so. Takes you ~5min to get deep and accelerate to Flank speed. Because they're doing big zigs, they execute a 90deg turn every 10min, and just so happen to execute that 90deg course change about the same time you go deep (technically, when you drop below the thermocline and lose them). Now you are in an unknowing tail chase with a 20kt target and started 20nmi behind. You blast forwards at 30 knots for 30 minutes, and when you pop up you're expecting the target to be 5nmi directly ahead of you. Surprise!

Now you're still paralleling the targets course at about 10nmi and are 18nmi away slant range. Target is ~15nmi ahead of you on parallel course. Do another 30min/15nmi sprint dead ahead and they zigged again as soon as you're under the thermocline (your luck sucks). However, that zig puts them dead ahead of you 5nmi away. (90deg zigs every 30min, crossing the base course at 45deg)

Great, you managed to catch them in open ocean after more than an hour. Now you can see if they're flying a Chinese flag and engage if they are.

 

[Ozair]

MSC Daniela Class, 14,000TEU, 165,000DWT, Cruise Speed 23.5Kts
CSCL Globe Class, 19,100 TEU, 185,000DWT, Cruise Speed 20.5kts

A look on Vesselfinder.com at the entire class for both shows no Daniela or Globe vessel sailing over 19kts and most between 13 and 18. A few were clearly close to port but most running along typical shipping lanes. The practical and economical speeds they travel are not the advertised cruise speeds the vessels are capable of.

For additional data points I also did the Star Class and a random selection of MkIV/V from Wallenius Wilhelmsen. All were at or below 18kts and most around 15kts.

 

[johnpjones1775]

How often did you hunt surface ships while you were in the Navy?

We did that a lot. Yes, as a missile submarine. Plus, my job was in control, either driving the boat or as part of Section Tracking Party when I wasn't driving. I've spent entire deployments doing this stuff because the Tactical Readiness Evaluation was at the end of the patrol.

You detect a contact at 30nmi. For argument's sake their course parallels yours at 20nmi range (just so that they're not 30nmi away from your course), placing them 15nmi behind your position on that parallel course (they're coming up behind you). For positive ID of the merchie target, you must get to within about 5nmi to see their national flag (merchies fly stupidly small flags).

You go deep and haul ass. Because you're not going to detect most skimmers below ~200ft due to the major thermocline, you lose contact as soon as you do so. Takes you ~5min to get deep and accelerate to Flank speed. Because they're doing big zigs, they execute a 90deg turn every 10min, and just so happen to execute that 90deg course change about the same time you go deep (technically, when you drop below the thermocline and lose them). Now you are in an unknowing tail chase with a 20kt target and started 20nmi behind. You blast forwards at 30 knots for 30 minutes, and when you pop up you're expecting the target to be 5nmi directly ahead of you. Surprise!

Now you're still paralleling the targets course at about 10nmi and are 18nmi away slant range. Target is ~15nmi ahead of you on parallel course. Do another 30min/15nmi sprint dead ahead and they zigged again as soon as you're under the thermocline (your luck sucks). However, that zig puts them dead ahead of you 5nmi away. (90deg zigs every 30min, crossing the base course at 45deg)

Great, you managed to catch them in open ocean after more than an hour. Now you can see if they're flying a Chinese flag and engage if they are.

So you have your panties in a bunch over a few hours of chasing?

 

[Scott Kenny]

So you have your panties in a bunch over a few hours of chasing?

For a single target that blundered into your detection circle.

Open oceans is not where submarines will hunt skimmers effectively.

 

[lastdingo]

Yes, that's my blog. Also linked in my profile here. Been around since 2007 and been guestposting on many other mil websites.

About ship cruise speed: Shanghai-Rotterdam container ships cruise at more than 20 kts. Big ships have a rather easy time to cruise at high speed. It's desirable (but not sufficient for survival) to have supply, invasion and evacuation convoys cruise quickly. Hence the importance of ASW helo dipping sonars; the only means to sanitise the area that can keep pace (sonobuoys are too expensive to do that with fixed wing aircraft).
Whether contianer ships cruise slower right now doesn't matter so much, cruise speeds aren't stable. They depend on scarcity of assets (ships and containers, sometimes waiting times at ports) and fuel prices. There are kind of fashions in regard to this.
https://transportgeography.org/cont...n-and-energy/fuel-consumption-containerships/

Conventional submarines can hunt on the open ocean when they form a line. The gaps may be as big as 100 nmi if they face slow targets or use submarine-launched anti-ship missiles (in a declared naval warzone with everyone considered a target). Germany used such wolfpacks in WW2 and it's often overlooked that they had extremely good hydrophones that permitted convoy detection at multiple times the horizon distance. Convoys did not slip through an intact wolfpack patrol line, but those were rarely fully deployed.
To use submarines like this is an underdog navy move, though.
Peer and superior navies should understand submarines (esp. SSNs) as assets that can go where other assets cannot operate. So one party in the war has underdog status in a maritime area (example USN Northern Yellow Sea, Russia Mediterranean, NATO in Soviet Barents Sea Bastion), but still wants to sink ships or divert resources there? Send subs.
For most regions it's just so much, much superior to send land-based air power to find, identify and engage ships.

 

[lastdingo]

Just a short read indicates the analysis is off...

All I read here is that you have a different opinion, for you didn't bring offer argument.

 

[johnpjones1775]

Yes, that's my blog. Also linked in my profile here. Been around since 2007 and been guestposting on many other mil websites.

About ship cruise speed: Shanghai-Rotterdam container ships cruise at more than 20 kts. Big ships have a rather easy time to cruise at high speed. It's desirable (but not sufficient for survival) to have supply, invasion and evacuation convoys cruise quickly. Hence the importance of ASW helo dipping sonars; the only means to sanitise the area that can keep pace (sonobuoys are too expensive to do that with fixed wing aircraft).
Whether contianer ships cruise slower right now doesn't matter so much, cruise speeds aren't stable. They depend on scarcity of assets (ships and containers, sometimes waiting times at ports) and fuel prices. There are kind of fashions in regard to this.
https://transportgeography.org/cont...n-and-energy/fuel-consumption-containerships/

Conventional submarines can hunt on the open ocean when they form a line. The gaps may be as big as 100 nmi if they face slow targets or use submarine-launched anti-ship missiles (in a declared naval warzone with everyone considered a target). Germany used such wolfpacks in WW2 and it's often overlooked that they had extremely good hydrophones that permitted convoy detection at multiple times the horizon distance. Convoys did not slip through an intact wolfpack patrol line, but those were rarely fully deployed.
To use submarines like this is an underdog navy move, though.
Peer and superior navies should understand submarines (esp. SSNs) as assets that can go where other assets cannot operate. So one party in the war has underdog status in a maritime area (example USN Northern Yellow Sea, Russia Mediterranean, NATO in Soviet Barents Sea Bastion), but still wants to sink ships or divert resources there? Send subs.
For most regions it's just so much, much superior to send land-based air power to find, identify and engage ships.

Yeah…so you cited yourself to support your post here. Lmao.

 

[Ozair]

All I read here is that you have a different opinion, for you didn't bring offer argument.

I'm not really interested in reviewing and critiquing a random blog for accuracy and logical reasoning. Were I to start that crusade I'd never finish...

I did provide arguments including facts supporting the speeds I have claimed but respectfully, citing your own blog as supporting evidence isn't evidence.

 

[johnpjones1775]

R

For a single target that blundered into your detection circle.

Open oceans is not where submarines will hunt skimmers effectively

For the last 20 years all I’ve heard is how submarines are these super deadly hunters and they’d sweep the seas of surface ships, but now you’re saying that they can’t even effectively sweep the seas of merchants?

 

[Scott Kenny]

For the last 20 years all I’ve heard is how submarines are these super deadly hunters and they’d sweep the seas of surface ships, but now you’re saying that they can’t even effectively sweep the seas of merchants?

They can, but not from open ocean.

Edit: also, most of that is talking about subs hunting carrier groups etc. Where you have external targeting data, plus a total group that's probably 100nmi wide. Makes it a lot easier to detect with own-ship sonars and then close in.

 

[DWG]

A look on Vesselfinder.com at the entire class for both shows no Daniela or Globe vessel sailing over 19kts and most between 13 and 18. A few were clearly close to port but most running along typical shipping lanes. The practical and economical speeds they travel are not the advertised cruise speeds the vessels are capable of.

For additional data points I also did the Star Class and a random selection of MkIV/V from Wallenius Wilhelmsen. All were at or below 18kts and most around 15kts.

So you've shown peacetime cruising speeds in the high teens are actually a thing. Want to bet a merchant proceeding independently in wartime (the situation we should be discussing) will stick to that if they have anything up to an extra five knots available?

 

[DWG]

For the last 20 years all I’ve heard is how submarines are these super deadly hunters and they’d sweep the seas of surface ships, but now you’re saying that they can’t even effectively sweep the seas of merchants?

Why hunt the plains when you can lurk by the waterholes?

 

[lastdingo]

Yeah…so you cited yourself to support your post here. Lmao.

No, I linked to it for further reading.

I'm not going to write long texts in a forum when I already published them years ago and they are still accessible there.

Also, I note that the outside link I showed about speeds was ignored, so I don't think that the two of you wrote in good faith when you mocked the links to the long form texts on the blog.

 

[lastdingo]

Why hunt the plains when you can lurk by the waterholes?

Imagine the issue is to supply Guam.
The Guam garrison could very well sweep the nearby waters with short range assets such as SH-60, but not far away on the ocean.

Or in other words; same reason why German wolfpacks didn't lure just outside of Liverpool port, but in the high atlantic.

 

[johnpjones1775]

They can, but not from open ocean.

Edit: also, most of that is talking about subs hunting carrier groups etc. Where you have external targeting data, plus a total group that's probably 100nmi wide. Makes it a lot easier to detect with own-ship sonars and then close in.

Been part of carrier battle groups, the CBG was never 100nmi wide, unless you’re referring to square miles maybe, but often escorts are just over the horizon from the carrier.

 

[johnpjones1775]

Why hunt the plains when you can lurk by the waterholes?

Because the waterholes have the rangers looking out for poachers

If subs are only lurking in the area of ports and major shipping routes it much easier to counter them.

If they’re lurking outside of those areas, then they have to be everywhere at once, meanwhile the sub only needs to be where it’s at.

 

[EmoBirb]

I feel like we've gone quite a bit off-course for several pages now given that only a select few posts over the recent pages have addressed the Constellation-Class (topic at hand) itself. Perhaps the discussion about the merchant marine and modern escort requirements etc. should be moved into its own thread for continued discussion?

 

[Ozair]

So you've shown peacetime cruising speeds in the high teens are actually a thing.

Nice... More the mid teens if you decided to review the evidence but C'est la vie.

Want to bet a merchant proceeding independently in wartime (the situation we should be discussing) will stick to that if they have anything up to an extra five knots available?

We were discussing convoys actually in which a convoy travels at the speed of the slowest vessel. Additionally there would be significant fuel considerations if the bulk of the vessels were travelling at the speeds you envision, the convoys would struggle to be refuelled at their destinations, ie Guam or other forward locations. As for independent operations, that seems highly unlikely especially in a conflict across the Pacific which is about the only current realistic scenario where resupply of the scale and size is required and resupply would be contested.

So to being it back to the Constellation, I could easily see it being the centre node of a fleet of unmanned vessels escorting convoys across the Pacific.

 

[DWG]

Because the waterholes have the rangers looking out for poachers

If subs are only lurking in the area of ports and major shipping routes it much easier to counter them.

The problem is when the 'waterholes' are hundreds of kilometres in size. Even if they're not physically constrained like individual ports, the Straits of Malacca, Bab el Mandeb, Suez, Panama or the Straits of Gibraltar, then the approaches to them work as a funnel for approaching traffic. You don't need to sit in the shallow waters of the straits or off the ports, just in their approaches, where the traffic is denser than in the open ocean.

Think of Western Approaches Command in WWII, it's the funnel into the west coast ports of the UK, but its area was about 2 million square miles. That's an awful lot of territory to cover with your escorts.

And unlike WWII, you now have RORSATs watching everything moving on the surface, potentially allowing the hunters to be cued with real time intel.

 

[johnpjones1775]

The problem is when the 'waterholes' are hundreds of kilometres in size. Even if they're not physically constrained like individual ports, the Straits of Malacca, Bab el Mandeb, Suez, Panama or the Straits of Gibraltar, then the approaches to them work as a funnel for approaching traffic. You don't need to sit in the shallow waters of the straits or off the ports, just in their approaches, where the traffic is denser than in the open ocean.

Think of Western Approaches Command in WWII, it's the funnel into the west coast ports of the UK, but its area was about 2 million square miles. That's an awful lot of territory to cover with your escorts.

And unlike WWII, you now have RORSATs watching everything moving on the surface, potentially allowing the hunters to be cued with real time intel.

Still easier to focus your ASW efforts on those funnels.

Raiders both subs and surface historically operated in more or less open ocean where it would be harder for the enemy to locate them, and they did just fine using only their intuition to guide them, meanwhile now raiders have the benefit of radar, satellites, etc.

 

[DWG]

We were discussing convoys actually in which a convoy travels at the speed of the slowest vessel.

Scott's original point was significant numbers of merchants are fast enough to transit independently, relying on speed rather than convoy for their defence. https://www.secretprojects.co.uk/threads/ffg-x.33649/post-805663

This was done in WWII, particularly with the fast liners (no losses), but also with fast cargo vessels, such as tankers. SSNs are faster than u-boats in WWII, but fast merchants are still a more difficult target to intercept.

 

[Firefinder]

Also while the SSNs are faster.

after 20 odd knots that becomes a major liability.

Cause not only does the SSN can't hear shit so can't find shit.

But any ships including other SSNs, like say a Virigina, in hunter killer sorties that have a sonar in an area the size of fucking ALASKA be able to hear you.

If they can hear you they can kill you.

Submariens are Ambush predators and if they can't set up an ambush, be it from 20 knot frieghters drunk driving or being haress by the Navy.

They become near useless for their historical role of ship interdiction.

 

[Scott Kenny]

Been part of carrier battle groups, the CBG was never 100nmi wide, unless you’re referring to square miles maybe, but often escorts are just over the horizon from the carrier.

I was assuming ASW escorts just over the horizon (~25nmi) from the AAW escorts which are just over the horizon (~25nmi) from the carrier. And then that much more on the far side of the carrier.

 

[Ozair]

Scott's original point was significant numbers of merchants are fast enough to transit independently, relying on speed rather than convoy for their defence. https://www.secretprojects.co.uk/threads/ffg-x.33649/post-805663

Did I reply to Scott? No I didn't. I was replying to a separate post which specifically discussed convoys.

This was done in WWII, particularly with the fast liners (no losses), but also with fast cargo vessels, such as tankers. SSNs are faster than u-boats in WWII, but fast merchants are still a more difficult target to intercept.

And when most aircraft weren't equipped with radar, no aircraft or ships had missiles capable of flying hundreds of miles, almost no homing torpedoes, no long range towed array sonar or pre-positioned sonar systems along choke points, no space based radar and imaging etc. It is a lot easier today to detect and target these independent ships than it has ever been before.

 

[DWG]

Did I reply to Scott? No I didn't. I was replying to a separate post which specifically discussed convoys.

As soon as you start discussing the speed of fast merchant ships it brings independent transit back into the discussion whether that's your intent or not.

And when most aircraft weren't equipped with radar, no aircraft or ships had missiles capable of flying hundreds of miles, almost no homing torpedoes, no long range towed array sonar or pre-positioned sonar systems along choke points, no space based radar and imaging etc. It is a lot easier today to detect and target these independent ships than it has ever been before.

It doesn't matter. Their defence isn't the difficulty of finding them, it's the difficulty of getting something in place to intercept them given their speed of advance relative to the hunters.

 

[johnpjones1775]

I was assuming ASW escorts just over the horizon (~25nmi) from the AAW escorts which are just over the horizon (~25nmi) from the carrier. And then that much more on the far side of the carrier.

Never seen any dedicated ASW escorts in a CBG.
Even when the OHPs were still in the fleet the only time I ever saw one actually operating with any other ships was when we film captain Philips.

I doubt the Connies would be used that way. They’d likely remain relatively close to the carrier as well. I could see a Connie being the dedicated plane guard ship (or whatever that role is called)

 

[johnpjones1775]

Also while the SSNs are faster.

after 20 odd knots that becomes a major liability.

Cause not only does the SSN can't hear shit so can't find shit.

But any ships including other SSNs, like say a Virigina, in hunter killer sorties that have a sonar in an area the size of fucking ALASKA be able to hear you.

If they can hear you they can kill you.

Submariens are Ambush predators and if they can't set up an ambush, be it from 20 knot frieghters drunk driving or being haress by the Navy.

They become near useless for their historical role of ship interdiction.

Do you think that merchant ships will magically teleport? Once you’ve found them you know where they could be at any given time based on their speeds…sprint for 30-60 minutes, slow listen see if they changed course, adjust if necessary, sprint, slow, listen, adjust, repeat.

Hell if there’s no escorts no reason to even be submerged. Sprint near the surface and pop a radar up to watch them instead of listening.

 

[Ozair]

As soon as you start discussing the speed of fast merchant ships it brings independent transit back into the discussion whether that's your intent or not.

I wasn't aware I need to take the entire concept of global conflict into consideration when commenting on a post... It still invalidates your point and your assertions on independent transit.

It doesn't matter. Their defence isn't the difficulty of finding them, it's the difficulty of getting something in place to intercept them given their speed of advance relative to the hunters.

Disagree 100%. If those ships are not transiting in threat zones then the whole discussion is worthless.

 

[DWG]

It still invalidates your point and your assertions on independent transit.

So exactly which part of "if a merchant can transit at a speed such that no submarine can intercept it then it can proceed independently of convoy" is invalid?

 

[DWG]

Hell if there’s no escorts no reason to even be submerged.

Mr MPA is not your friend.

 

[Firefinder]

Do you think that merchant ships will magically teleport? Once you’ve found them you know where they could be at any given time based on their speeds…sprint for 30-60 minutes, slow listen see if they changed course, adjust if necessary, sprint, slow, listen, adjust, repeat.

Hell if there’s no escorts no reason to even be submerged. Sprint near the surface and pop a radar up to watch them instead of listening.

And do You think the oddles of ASW assets are at base playing video games?

Cause that is assuming that there's No Lurking SSN looking for Subs using the Frieghter as unknowing bait.

Or No Patrol Planes doing as well.

That 30 to 60 minute sprint is ringing the dinner bell for every ASW asset in that area of the Sea boss. That long enough for a Sturgeon or Marlin to locatize you, let allow a Virginia or Posideon.

Cause now EVERYONE WITH A SONAR KNOWS YOU THERE.

You are no longer the Ambusher.

But the Ambushy.

And the P8 or Virginia are now looking in you general location waiting for you to try that again so they can shove a torp into you prop.

YOu are now on the clock to get in range of the Frieghter without sprinting.

Cause as soon as you try to Sprint again or heaven forbid try to radiate.

You be hearing torpedo in the water.

 

[johnpjones1775]

So exactly which part of "if a merchant can transit at a speed such that no submarine can intercept it then it can proceed independently of convoy" is invalid?

…the entire premise.

 

[johnpjones1775]

And do You think the oddles of ASW assets are at base playing video games?

Cause that is assuming that there's No Lurking SSN looking for Subs using the Frieghter as unknowing bait.

Or No Patrol Planes doing as well.

That 30 to 60 minute sprint is ringing the dinner bell for every ASW asset in that area of the Sea boss. That long enough for a Sturgeon or Marlin to locatize you, let allow a Virginia or Posideon.

Cause now EVERYONE WITH A SONAR KNOWS YOU THERE.

You are no longer the Ambusher.

But the Ambushy.

And the P8 or Virginia are now looking in you general location waiting for you to try that again so they can shove a torp into you prop.

YOu are now on the clock to get in range of the Frieghter without sprinting.

Cause as soon as you try to Sprint again or heaven forbid try to radiate.

You be hearing torpedo in the water.

Again the US navy has said they can’t protect merchants. It will be like the beginning of WWII all over again. There will be gaps in coverage.

 

[Ozair]

So exactly which part of "if a merchant can transit at a speed such that no submarine can intercept it then it can proceed independently of convoy" is invalid?

Because 1, the merchants aren't transiting at speeds where no submarine can intercept them and 2, as you allude to in the very next post there are other assets other than submarines. You reference a friendly MPA but to assume that there are not adversary assets available, including long range UCAVs that can identify and at range prosecute targets or direct assets to those targets, is naïve and ignores technological progress made since the 1940s.

 

[DWG]

Because 1, the merchants aren't transiting at speeds where no submarine can intercept them and 2, as you allude to in the very next post there are other assets other than submarines. You reference a friendly MPA but to assume that there are not adversary assets available, including long range UCAVs that can identify and at range prosecute targets or direct assets to those targets, is naïve and ignores technological progress made since the 1940s.

Fast independents weren't immune to being intercepted in WWII, but it came down to chance and the u-boat being in the right place to start with, and in hundreds of voyages by the fast troopships it never happened. That still holds, it's a geometry problem, not a technology problem. If merchant and submarine have similar speeds of advance, then it becomes physically impossible to intercept them outside of a specific set of starting positions.

And yes, there are other assets, but in many cases they can be ruled out. A western ship in the Atlantic or Indian Ocean is unlikely to encounter hostile MPAs. Yes, there are areas where you can't rely on that, but you aren't going to be taking a convoy inside the First Island Chain any more than you're going to be routing a fast independent there.

 

[johnpjones1775]

Fast independents weren't immune to being intercepted in WWII, but it came down to chance and the u-boat being in the right place to start with, and in hundreds of voyages by the fast troopships it never happened. That still holds, it's a geometry problem, not a technology problem. If merchant and submarine have similar speeds of advance, then it becomes physically impossible to intercept them outside of a specific set of starting positions.

And yes, there are other assets, but in many cases they can be ruled out. A western ship in the Atlantic or Indian Ocean is unlikely to encounter hostile MPAs. Yes, there are areas where you can't rely on that, but you aren't going to be taking a convoy inside the First Island Chain any more than you're going to be routing a fast independent there.

So the troop ship teia maru wasn’t sunk by a submarine?
Or how about the tamatsu maru? She wasn’t sunk by a submarine?

Need a lot less luck with things like satellites and long range aircraft overhead locating targets.

 

[shin_getter]

You detect a contact at 30nmi. For argument's sake their course parallels yours at 20nmi range (just so that they're not 30nmi away from your course), placing them 15nmi behind your position on that parallel course (they're coming up behind you). For positive ID of the merchie target, you must get to within about 5nmi to see their national flag (merchies fly stupidly small flags).... [much blind chasing after]


Now you're still paralleling the targets course at about 10nmi and are 18nmi away slant range. Target is ~15nmi ahead of you on parallel course. Do another 30min/15nmi sprint dead ahead and they zigged again as soon as you're under the thermocline (your luck sucks). However, that zig puts them dead ahead of you 5nmi away. (90deg zigs every 30min, crossing the base course at 45deg)

Seems like one should build a loitering munition that checks out the flag before putting in the hole. This should end this clumsy dancing. Alternative a recon drone that can communicate with a underwater sub, but that is technically much more difficult though i guess a buoy wired to the sub can do it.

Float upwards munitions launchers with some so-so sensor also seems like a better way to enact a blockade than stationing a expensive sub at it. The sub fleet would just be transport, like the historically very successful mining ops.