You are using an out of date browser. It may not display this or other websites correctly. You should upgrade or use an alternative browser.
alternatehistory.com
This happens a day before the May 7 OTL carrier action:
On May 6 Fletchers carriers were sighted by a Kawanishi reconnaissance flying boat from Tulagi, the sighting report was incorrect (in terms of heading) and Takagi concluded he wasn't close enough to attack that day. However at the end of the day the carrier task forces ended up only 70 nautical miles apart.
But what if the sighting report was correct or Takagi just goes for it anyway and the Shokaku and Zuikaku launch a full strike late in the day of the 6th. Lets assume the planes find the American carriers and the damage that was inflicted on the next day OTL is inflicted here plus one more torpedo in the side of the Yorktown (a few extra Japanese planes are available without the attrition of the OTL Neosho strike).
The Lexington sinks eventually as OTL and the Yorktown is out of action longer than OTL. Shokaku and Zuikaku are intact but lose many aircraft in the strike as in OTL. Shoho is also still intact.
What happens next????
Some thoughts:
1) Can the Japanese really invade Port Moresby then???? OTL there was significant Allied land based air based around in Port Moresby and Townsville, even if these couldn't pull of strike against carriers they might be able to damage transports or strike landing sites.
2) How does this affect Midway??? Its still a well defended strong point by US marines in base defence mode even if the Amercians can't oppose an invasion with naval forces. (The Satatoga is almost ready though)
3) Does this shake Amercian confidence in the benefits of their code reading ability (with butterflies down the road)????
4) The Japanese carrier force is still intact, does this preclude significant naval action until the Essex class carriers are complete?????? (or do the Japanese just keep trying to expand the territory under the control and a Midway like defeat just happens later at New Caledonia or some other such place)