You're forgetting Scout Number 4 was a half-hour late taking off. It will not reach it's maximum search range for another hour yet.
8 seconds sound clip from the Midway (1976) movie soundboard.
You can hear this line at 01:19:41.035 in the Blu-ray version of the movie.
Quote context
[...]
- They should all be taken below immediately and rearmed with bombs, sir.
- We must make certain that no air attacks against us can be mounted from Midway.
- Sir, Lieutenant Tomonaga's request is also a warning.
- Midway is still a threat to us.
- So are the American carriers, Kusaka.
- If they are nearby, yes, sir.
- But our scouts have been gone for over two hours now, they've reported nothing.
- Fifty-seven planes on the line, sir. The Hornet will probably launch about the same number.
- What's the position of the enemy carriers?
[...]