Wasn’t there already great emphasis on U-boats?
The Navy was never Hitler’s favourite branch of the armed forces;
“The navy’s operational planning was based upon a fleet that could not be ready before 1943. In fact, the 1939 Z-Plan – halted at the start of the war – would leave Germany with severe limitations at sea until 1946. And within the confines of that plan, the building of U-boats necessary for an economic blockade of Britain was deliberately neglected by Hitler in favour of the interests of the army.”
(Kershaw, Hitler 1936-45 Nemesis).
The revolutionary Type XXI for example which could operate submerged for far longer than any previous u-boat came so late that only four were combat ready by the war’s end. Imagine a fleet of those in the Battle of the Atlantic.
Not until later. Plan Z Plan Z - Wikipedia
called for 10 battleships, etc.
This is my vote. Hitler was not a big fan of letting facts get in the way.
Add that to the fact that even (or, especially) rational people should question ANY information that purports to come from or otherwise predict the future.
As others have said, there wasn’t an emphasis on submarines. Germany wanted to build a big regular navy - but the resources for this were always going someplace else. Submarines got built, by default, not because they were prioritized but rather because they were small ships that used fewer resources.
Make sure the time machine is tuned up for multiple return trips. Because as soon as he changes one thing on the list, everything that follows is thrown into a cocked hat.
Nope, there’s only so much we’re gonna do for this bastard.
Bad phrasing on my part: what I meant was that making sure the time machine was tuned up would be one of the things he should be certain to do. Myself, I’d tune the time machine so that it dumped him in the middle of a pack of hungry Deinonychus.

Thinking it over, the most obvious connection Hitler would make would be that Germany should have developed its own atom bomb. The German researchers at the time felt that no atom bomb could be built within the time frame of the war so atomic research became a minor program. But a time traveling Hitler would see that an atom bomb had been built by 1945 and when he went back, he’d make Germany’s atomic program a priority.
And then he’d almost certainly lose the war because of it. It would never occur to Hitler that just because the United States had been able to build a bomb by 1945 didn’t mean Germany could do the same. Hitler would just assume that Germany could do anything any other country could do and do it better. But the reality is that the United States was probably the only country that had the resources to build an atom bomb during the war.
So Hitler would have just been throwing resources into a program that wasn’t going to produce results in time. And the loss of the resources would have affected the rest of Germany’s armed forces. Germany would still be only halfway to building an atom bomb when the allied powers overran Germany in 1944.
What if he started in 1933, made the bomb a priority?
At the same time only taking the “low hanging fruit” of expansion - waiting for the more difficult parts until he had the bomb?
A combination of keeping more scientists in the country (by being more moderate), having more resources to put into the programme, and the US not putting such resources into A-Bomb development (as they didn’t have a need to) may well see Germany get the bomb well before anyone else - then it’s pretty much over isn’t it?
Personally I have always felt that Britain and France screwed over Germany so bad by blaming them for WW1 and pushing such harsh reparations that a WW2 was inevitable.
Plus the 1930’s was an era where many things were changing with the rise of socialism and nationalism and such.
So war of some type was to come.

What if he started in 1933, made the bomb a priority?
At the same time only taking the “low hanging fruit” of expansion - waiting for the more difficult parts until he had the bomb?
A combination of keeping more scientists in the country (by being more moderate), having more resources to put into the programme, and the US not putting such resources into A-Bomb development (as they didn’t have a need to) may well see Germany get the bomb well before anyone else - then it’s pretty much over isn’t it?
The problem was Germany was starting from deep down in a hole. They had pretty much lost all their military after World War I. So they needed to spend a lot on just getting back up to military equality with the rest of Europe
There’s no way they could do that and develop an atomic bomb. If they had made an atomic program a priority, they might have had an atomic bomb in 1938 - but they wouldn’t have had an army, an air force, or a navy. And the early atomic bombs were not war winners by themselves.

Personally I have always felt that Britain and France screwed over Germany so bad by blaming them for WW1 and pushing such harsh reparations that a WW2 was inevitable.
Plus the 1930’s was an era where many things were changing with the rise of socialism and nationalism and such.
So war of some type was to come.
I’ve said this before. The Versailles Treaty was not a particularly harsh treaty. It was just German propaganda that claimed it was unreasonable.
The terms of the Versailles Treaty were milder than the terms Germany dictated to Denmark in 1864, Austria in 1866, or France in 1870. They were milder than the terms Germany dictated to Russia in 1918. They were milder than the terms Germany announced in 1918 that it planned on dictating to Britain and France. They were milder than the terms the Allies dictated to the other losing powers in 1918 like Austria-Hungary or the Ottoman Empire. And they were much milder than the terms the Allies would dictate to Germany in 1945.

What if he started in 1933, made the bomb a priority?
At the same time only taking the “low hanging fruit” of expansion - waiting for the more difficult parts until he had the bomb?
A combination of keeping more scientists in the country (by being more moderate), having more resources to put into the programme, and the US not putting such resources into A-Bomb development (as they didn’t have a need to) may well see Germany get the bomb well before anyone else - then it’s pretty much over isn’t it?
Upon reflection, it occurs to me that there’s an even deeper problem with this hypothetical than resources. Nobody was going to start an atomic weapons program in 1933 even if they had all the money in the world. The science just didn’t exist in 1933. Nuclear fission was discovered in December 1938 (in Germany). So 1939 was the earliest date when anyone could start working on an atom bomb. And Hitler had other matters on his mind by then.

Upon reflection, it occurs to me that there’s an even deeper problem with this hypothetical than resources. Nobody was going to start an atomic weapons program in 1933 even if they had all the money in the world. The science just didn’t exist in 1933. Nuclear fission was discovered in December 1938 (in Germany). So 1939 was the earliest date when anyone could start working on an atom bomb. And Hitler had other matters on his mind by then.
But based on the information, Hitler may be able to point the scientists toward nuclear fission and then the bomb, all at an earlier date.

Stop using the Enigma machine.
Radar is important. Get working on it.
There’s oil in Libya.
Forget about surface ships. Build submarines.
A number of technical and tactical and strategic decisions made with hindsight would change the outcome of the war. Hitler doesn’t take advice well, but consider the following:
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The enigma rotors are changed every week, except some that give out false intelligence.
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Dunkirk results in the elimination and capture of the soldiers in the pocket and peace is sought with the UK.
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Operation Sea Lion and the Battle of Britain are never planned for or executed, leaving the Luftwaffe basically untouched.
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The resources for Bismarck, Tirpitz, and the pocket battleship raiders are instead invested in submarines.
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The invasion of Russia starts early and with more troops with winter clothing and better air cover and the Nazis don’t kill off the Soviet citizenry, capturing Moscow, St. Petersburg, Kiev and Stalingrad, leaving the transportation hubs in German hands, instead of stopping short. The “liberated” people, not being killed by the Nazis, turn on Stalin, leaving everything west of the Volga pacified for the Germans. Kursk never happens.
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In the 30s the Nazis assassinate Zukov.
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Hitler knows that he doesn’t get anything from declaring war on the US, and doesn’t do it.
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Hitler makes an all out effort to capture Gibralter, leaning much harder on Franco.
I become a bar of soap.

But based on the information, Hitler may be able to point the scientists toward nuclear fission and then the bomb, all at an earlier date.
Hitler was an art student. I doubt he was capable of grasping the details of nuclear fission enough to describe them to physicists. And even if he was, why would physicists listen to him? Even Einstein doubted a chain reaction was possible in 1933. What’s Hitler going to do? Tell everyone he saw it all when he was traveling in time?

- Hitler makes an all out effort to capture Gibralter, leaning much harder on Franco.
And French Somaliland (aka Djibouti). It was easily within Axis reach early in the war but the British sent reinforcements and secured the area.
If the Germans held Gibraltar and Djibouti, they could close off the entire Mediterranean region and after that it would have just been a matter of mopping up the garrisons.

By the way, I think there is a very small chance that, given full information about WWII and the Holocaust, Hitler could simply resign or pursue an entirely different path as a leader in 1933.
We are used to seeing the end state of Hitler as the essence of the man, but he reached that point step by step. Using power got him used to using it more, and doing a little evil prepared him for greater evil. It’s possible that, in 1933, he didn’t really want a world in ruins and millions upon millions dead. It’s possible that seeing the final result would be a big shock to the system that he could not process.
I would put the chance of that at about, oh, 1%. It’s vanishingly small but still there.
I enjoy toying with a scenario like this – however improbable. The idea is appealing, of Hitler finding 1939 - 45 as revealed, too horrible to contemplate. One imagines him giving up politics, and maybe becoming a monk – or spending the rest of his life as a warden on a nature reserve in a remote corner of Germany…

I’ve said this before. The Versailles Treaty was not a particularly harsh treaty. It was just German propaganda that claimed it was unreasonable.
The terms of the Versailles Treaty were milder than the terms Germany dictated to Denmark in 1864, Austria in 1866, or France in 1870. They were milder than the terms Germany dictated to Russia in 1918. They were milder than the terms Germany announced in 1918 that it planned on dictating to Britain and France. They were milder than the terms the Allies dictated to the other losing powers in 1918 like Austria-Hungary or the Ottoman Empire. And they were much milder than the terms the Allies would dictate to Germany in 1945.
No. The reparations were (wiki):In 1921 the total cost of these reparations was assessed at 132 billion Marks (then $31.4 billion or £6.6 billion)…The treaty stripped Germany of 25,000 square miles (65,000 km2) of territory and 7,000,000 people… also Germany to renounce sovereignty over former colonies and Military restrictions.
The Franco Prussian war ended with France paying “The indemnity was 5 billion francs (£200 million pounds sterling or $1000 million dollars)”. In other words, the German payout was 31 times what the French payout was. The French gave back 14,496 km in the highly disputed territory of Alsace-Lorraine with about 1.8MM people- so the Germans gave up over three times the people, and about twice as much territory.
Germany made no “terms Germany announced in 1918 that it planned on dictating to Britain and France”. (Germany had pretty much lost the war by that point)
As for the Peace of Prague which ended the Austro-Prussian War :“The treaty was lenient toward the Austrian Empire because Otto von Bismarck had persuaded Wilhelm I that maintaining Austria’s place in Europe would be better in the future for Prussia than harsh terms, as Bismark realized that without Austria Prussia would be weakened in a relatively hostile Europe. At first, Wilhelm I had wanted to push on to Vienna and annex Austria but Bismark stopped him, even threatening to resign at one point. Indeed, it was this relative cordiality with Austria that caused the clamouring factions of Europe in 1914 that led to the Great War.[1] Austria only lost Venetia, ceded to Napoleon III of France, who in turn ceded it to Italy.” Austria paid no reparations.
As for the reparations that were to be paid by Russia to Germany due to the Treaty of Brest-Litovsk? six billion German gold marks. Which is .04% of the 132 billion Marks France demanded from Germany.
I think he might have tried to go a bit more slowly with his plans.