What's accurate
Generally, it's fairly accurate, and tracks what was known of the battle by the mid-1970's, most notably Walter Lord's Incredible Victory (my personal favorite nonfiction book), which was informed by Mitsuo Fuchida's memoir, published in the 1950's, which becomes important later. Specifically, it accurately relates:
- the effect of the Doolittle Raid on Japanese planning
- the codebreakers' activities uncovering Japanese intentions
- Nimitz' efforts to defend Midway, including accepting Halsey's nomination of Spruance, and insisting on sending the damaged Yorktown
- the decisionmaking process by Nagumo during the battle
- the decisionmaking process - in general - on the U.S. carriers
- the carriers' squadrons' attacks on the Japanese carriers (the attacks by Midway squadrons are not shown)
What's not accurate
First, the Charlton Heston character, "AirOps" on Nimitz' staff is fictional, but at various stages in the movie plays a role that is identifiable with a historical character.
At the beginning of the movie he approximates the intermediary role of Cdr Edwin Layton, Nimitz' intelligence chief, who - against Washington's (the Redmon brothers) express directions to the contrary, obtained and relayed Rochefort's cryptanalysis results and recommendations directly to Nimitz. Captain Redmon in Washington, who had no cryptanalysis experience, wanted to interpret the intelligence himself and have only his analysis and recommendations sent to CinCPac - and not the decrypts and analysis from the various codebreaking stations, of which Hypo in Hawaii was only one.
There was no senior officer from Nimitz' staff assigned to Fletcher on the Yorktown at Midway - although there had been an intelligence offer assigned at Coral Sea, whose work for Fletcher was the genesis for the leak of the fact that the Navy was reading the Japanese code. As Alvin Kernan, an Enterprise aircraft ordnanceman noted in both his books, that was open knowledge on the ships at Midway, and recent scholarship has traced the leak back to Fletcher's staff's handling of the information he received from CinCPac on the ride back to Pearl Harbor after Coral Sea.
Heston's character also approximates the role of the squadron leader from the Yorktown who led its surviving SBDs to the Enterprise for the afternoon attack on the Hiryu. However in reality the aircraft never landed on Yorktown as it was under attack, and instead were simply redirected to Enterprise, where, less two aircraft that ran out of fuel or were shot down by AA fire while circling, they made up half of the strike that sank the Hiryu.
Finally, as the film doesn't show the Yorktown being abandoned, or ever mention its abandonment or sinking, the "Matt Garth" character's death at the end more or less approximates it, at a substantial savings in special effects costs.
Second, while Rochefort did wear a smoking jacket and carpet slippers, they were not indications of eccentricity, as Hal Holbrook played him in the movie. He was working long hours on concrete floors in a room that was decidedly chilly in order to keep the computing equipment operating efficiently. He was a very serious officer, and not at all eccentric. He passed away one month after the movie came out, incidentally.
He was most certainly scapegoated by the DC naval intelligence community after the battle for being right. King turned down Nimitz' recommendation that he receive a medal for his intelligence work, and he was transferred to command a floating drydock in San Francisco. (I am not making that up). He never went to sea again.
Interesting note: Henry Fonda worked as an aide for Nimitz briefly at CinCPac headquarters on Guam in 1944-45. It was not, Fonda recalled, a close relationship, and he assumed Nimitz was irritated at getting a Hollywood star placed on his staff, however briefly. But it makes his portrayal fascinating to me, because I wonder how much of it is mimcry of a historical figure he actually knew.
Second interesting note: both Yamamoto and Nimitz were missing fingers. Yamamoto lost two during the battle of Tsushima, and Nimitz while showing the operation of engines during a tour of an engine room in the 1920's.
Post-movie comments
The movie's reflection of the battle as a miraculous win - as did all books to that time - was characterized by later authors as "Incredible Victory disease" - a phrase Walter Lord would have loved, I'm sure, because more recent scholarship showed that wasn't the case. I'm not being sarcastic - I met Lord at a Nimitz Symposium in 1992, and he was fascinated by the scholarship that was coming out even then - he would have been so pleased to have his title tweaked.
In 2005 Shattered Sword: The Untold Story of the Battle of Midway provided the results of analysis of the Japanese side, including computer calculations of the activity on the Japanese carrier hanger decks as they rearmed aircraft using a limited number of bomb and torpedo trucks and aircraft and bomb elevators, which resulted in the conclusion that when Fuchida wrote in the 1950's that the Akagi and other carriers' flight decks were full and they were just about to launch what would have been a fatal strike on the US task forces when they were hit by the dive bombers - he was lying. He was attempting to portray fate as having intervened at the decisive moment in the battle, when the truth was that the Kido Butai was nowhere near ready to launch an airstrike when the dive bombers arrived. The timing of their arrival meant absolutely nothing to the outcome of the battle.
This underscored the flaw in the Japanese plan that was apparent even in the painfully rigged war games that took place on the Yamato several weeks before, when the officer playing the American forces put his carriers almost exactly where Spruance and Fletcher later would, and sank two of the four Japanese carriers with his initial strike - which with the exception of Dick Best's single bomb which sank the Akagi - was exactly what happened on the morning of June 4. Given the flammability of Japanese carriers while operating aircraft, if they were spotted by US carriers before the US carriers could be destroyed, they would likely be sunk. There was really no Incredible Victory to the battle - Nimitz had more aircraft, an island target that distracted Nagumo and divided his striking power, and a fairly precise knowledge of how the battle would unfold. All he had to do was launch before the Japanese carriers did, and it's hard to envision a situation where he would not be able to.
The only thing that really made the battle close was the poor performance of the air staff on task Force 16, most notably the bad leadership of the Hornet's air group. Led by CHAG Stan Ring, Hornet's dive bombers succeeded in missing the Japanese carriers during both strikes in June 4 (he even missed getting in a plane for the afternoon strike), and the near complete failure of the Enterprise's dive bombers to locate the carriers. The only reason they even had the chance to do so (the famous scene of McCluskey seeing the Arashio is accurate) was because Spruance overruled Halsey's chief of staff Miles Browning who wanted them to keep circling to form up with the torpedo planes. After a delay of nearly an hour, Spruance sent them along over Browning's objections. The more experienced Yorktown launched an hour later than Enterprise and Hornet, but placed all three of its squadrons directly on top of the Japanese carriers at the same time. Even though its squadrons were in some cases flying with each other for the first time, they communicated well before the launch and launched in reverse order, which gave them far more fuel. Enterprise lost half its two squadrons to fuel exhaustion - Yorktown lost two aircraft of its one squadron.
Interesting note - Miles Browning's grandson is Chevy Chase.
The real story of the "flight to nowhere" of the Hornet's squadrons didn't really become clear till after 1976 in part because there were never any squadron or other reports written by Ring or Mitscher, so what actually happened was not pieced together until recently. The movie focuses on what is known - that Torpedo 8 flew straight to the Japanese carriers, but not until recently have historians finally settled on the theory that Ring deliberately flew north of the reported position, hoping to catch the "other two" Japanese carriers. We forget that at the time he left, only two had been sighted, and Nimitz had told them there were four - and possibly five. But he didn't - and wouldn't - tell Waldron or anyone else why he was flying the heading he was. As his navigation was known to be erratic, Waldron finally told him - on an open channel overheard by many - to go to hell and turned left to fly straight to the reported position of the carriers. He likely had no idea that Ring and possibly Mitscher were probably sending him north of the reported position to catch the two carriers they (incorrectly) assumed would be behind the reported location.
Shattered Sword found one other interesting fact that undermined what had been a great dramatic point in the movie, and that was the role of the cruiser Tone's Scout #4. For 60 years historians have blamed Scout #4's delay in launching for the failure of the Japanese to launch their strike at the American carriers before the dive bombers hit. But, as noted above, it would have made no difference when they knew, because as long as they were landing the returning strike planes and cycling their CAP to respond to the continuing strikes from Midway they could not have launched.
But paradoxically, the late launch actually gave them earlier notice, and was an enormous stroke of luck. In order to get back on schedule, the Tone's pilot only flew partway out on his search leg, then turned to fly across his assigned sector before returning. It was while flying across his sector that he spotted the Yorktown. Had he flown his full search arc, then across, then back, he either would not have spotted the US task force at all, or would have seen it substantially later. Again, Fuchida assigned the fact that the plane assigned to the crucial arc was late to fate, and Lord and other historians followed his lead - but without checking where on his flight he spotted the US carrier.
It's really interesting how inaccurate I harped on the movie being in 2006, but by 2016 I appreciated how it got the big points right. If it got the Star Trek remastered treatment on special effects, the dramatic portion would work pretty well.