Coral Sea: Full Kido Butai vs Four US Carriers

[Marshmallow Waffles]

In May 1942, the Japanese still have all six carriers of the Kido Butai, as well as several light carriers, but squandered their numerical advantage by splitting up their carriers on several operations instead of using them all together. So, this what if asks if the Japanese had realized, "Okay, we have the biggest hammer, let's just use it to completely annihilate whatever the Americans send to oppose us." Since the Port Moresby operation is their first good chance to sink the American carriers, Yamamoto decides to send all six carriers on the operation.
Now, the American code breaking would probably get a very good idea that the Japanese are sending the whole Kido Butai there. Nimitz would have likely rushed Task Force 16 south to join Task Force 17. Giving the Americans four carriers against the Japanese six (not counting Shōhō). This would also put Halsey in command for the battle, for better or worse.
The question is then, how does this battle develop? With the total number of carriers going from four to ten, each side has a massively higher number of planes to throw at each other when the battle properly develops, with a likelihood of multiple strikes if both sides have enough decks still floating. (If my math is right, both sides have enough firepower to decimate each other in one semi-concentrated strike).
Or, am I missing something that makes this whole scenario ridiculous?

 

[CV12Hornet]

I mean, it is a scenario that can't happen. The USN can't get four carriers south, because Saratoga is laid up in drydock, Enterprise and Hornet spent all April on the Doolittle Raid, and there weren't enough oilers on hand to support four carriers that far away from Pearl Harbor anyway. On the Japanese side, the Kido Butai's older carriers were in desperate need of some TLC after five months of running all across the Pacific playing fireman.

In any case, this is Japan's battle to win, because the Americans in 1942 had a bad habit of expending their crucial first strikes on expendable light carriers, leaving the main Japanese striking power intact. The most likely outcome, IMO, is that one American task force vents its fury on Shouho, while the other manages to hit two Japanese fleet carriers before a return strike from the Kido Butai knocks out one of the American task forces entirely. The Americans are forced to retreat in face of Japanese carrier superiority, the Americans losing two carriers sunk, while the Japanese lose Shouhou sunk and probably one of the fleet carriers sunk and the other damaged and in line for several months of drydock time.

 

[Marshmallow Waffles]

I mean, it is a scenario that can't happen. The USN can't get four carriers south, because Saratoga is laid up in drydock,

Yeah, Saratoga is missing this battle no matter what the Americans do really.

Enterprise and Hornet spent all April on the Doolittle Raid, and there weren't enough oilers on hand to support four carriers that far away from Pearl Harbor anyway.

Didn't they send Task Force 16 south in OTL (I'm pretty sure they only missed the battle by a few days). Doesn't this mean that there were enough oilers, since they were intending to operate them all in the South Pacific at the same time?

On the Japanese side, the Kido Butai's older carriers were in desperate need of some TLC after five months of running all across the Pacific playing fireman.

Right, I had glossed over that detail in my mind when coming up with the idea. Ah well, happens to all of us. Perhaps if Operation MO gets delayed until they're ready? Which also conveniently would help solve Enterprise and Hornet coming from the Doolittle Raid.
What kind of state were those four Japanese carriers in? I can't imagine it would have been good considering.

In any case, this is Japan's battle to win, because the Americans in 1942 had a bad habit of expending their crucial first strikes on expendable light carriers, leaving the main Japanese striking power intact. The most likely outcome, IMO, is that one American task force vents its fury on Shouho, while the other manages to hit two Japanese fleet carriers before a return strike from the Kido Butai knocks out one of the American task forces entirely.

If the Americans find the Kido Butai at the same time as they find Shōhō, wouldn't they just ignore the light carrier in favor of throwing everything they can at the six carriers coming right at them?
(Or if they find Shōhō the day before as per OTL without finding the Kido Butai, then she probably gets annihilated.)

The Americans are forced to retreat in face of Japanese carrier superiority, the Americans losing two carriers sunk, while the Japanese lose Shouhou sunk and probably one of the fleet carriers sunk and the other damaged and in line for several months of drydock time.

I agree that the Americans are liable to lose at least two carriers barring some Midway-style shenanigans, and maybe even with that. But I imagine if they successfully throw four carrier air groups at the Kido Butai, surely they would do more damage than sinking only one of the fleet carriers.

 

[CV12Hornet]

If the Americans find the Kido Butai at the same time as they find Shōhō, wouldn't they just ignore the light carrier in favor of throwing everything they can at the six carriers coming right at them?
(Or if they find Shōhō the day before as per OTL without finding the Kido Butai, then she probably gets annihilated.)

Yes, but that's a big assumption given the state of aerial reconnaissance this early in the war.

I agree that the Americans are liable to lose at least two carriers barring some Midway-style shenanigans, and maybe even with that. But I imagine if they successfully throw four carrier air groups at the Kido Butai, surely they would do more damage than sinking only one of the fleet carriers.

Yes, but I was operating under the assumption that two air groups will be busy annihilating Shouhou.

 

[CaptainCalvert]

One of the practical considerations is that splitting the forces allows them to undertake more operations. 3 carriers would still be a powerful force, and a 4/2 split could also be considered if there was a lesser objective. Keeping all six together limits flexibility, and even though this force is able to beat all comers, this may not help if the enemy is winning elsewhere or if your progress is falling behind schedule.

 

[Dorknought]

While code breaking hadn't yielded full disclosure of Japanese plans, the information they did have was that an operation was planned. The options explored were a attack on Darwin or the Torres Strait, an attack on New Caledonia or Port Moresby. The last was assumed as the target as only part of the KB was committed (thought to be Zuikaku, Shokaku and Kaga). They had assessed that an attack on New Caledonia would entail a Fleet Action and that the whole IJN fleet would be committed which it wasnt. Therefore if the whole KB was committed AND that US intelligence could detect this then the US carriers would be far to the South East and not in the Coral Sea to counter a Japanese invasion of Port Moresby as they would be covering the assumed invasion of New Caledonia.

 

[Marshmallow Waffles]

One of the practical considerations is that splitting the forces allows them to undertake more operations. 3 carriers would still be a powerful force, and a 4/2 split could also be considered if there was a lesser objective. Keeping all six together limits flexibility, and even though this force is able to beat all comers, this may not help if the enemy is winning elsewhere or if your progress is falling behind schedule.

Fair point. Though with the decisive battle doctrine the Japanese have, concentrating all six together to annihilate whatever comes their way and inflict the decisive battle they so sought makes some sense? Even at the cost of delaying future operations a bit? And they operated five together for an operation at one point.

 

[Marshmallow Waffles]

While code breaking hadn't yielded full disclosure of Japanese plans, the information they did have was that an operation was planned. The options explored were a attack on Darwin or the Torres Strait, an attack on New Caledonia or Port Moresby. The last was assumed as the target as only part of the KB was committed (thought to be Zuikaku, Shokaku and Kaga). They had assessed that an attack on New Caledonia would entail a Fleet Action and that the whole IJN fleet would be committed which it wasnt. Therefore if the whole KB was committed AND that US intelligence could detect this then the US carriers would be far to the South East and not in the Coral Sea to counter a Japanese invasion of Port Moresby as they would be covering the assumed invasion of New Caledonia.

Huh, I haven't ever heard of this before. Do you happen to have the source? Or somewhere I could find more details about that? I would love to learn more.

 

[Dorknought]

Do you happen to have the source?

From "Battle Surface, :Japan's Submarine War Against Australia by David Perkins). Note the timing, Only Yorktown and Lexington would make the initial battle as Enterprise and Hornet only just making it back from the Doolittle Raid.