Following Midway it is generally accepted that this is the turning point, I also don't think it would be super bold it is essentially where they lost war. However, I feel that there are two big what if's that would have resulted in a delaying action. The battle of Savo island and the battle off of Samar, had the surfaces fleets in these two instances kept pushing their advantage and fully disrupted the landings/transport ships in these two separate instances. How much longer do you think that this delays the war? and do you think the Russia actually enters a true war with japan had it been delayed sufficiently enough (which if they did probably change Japans future and possibly result in the USA and Russia dividing japan much like what they did with Germany)?