After the US Navy's defeat in the First Battle of the North Pacific, the Americans withdrew to the US West Coast to lick their wounds and prepare for another attempt. Having learnt valuable lessons in that battle, they transferred all of their carriers from the Atlantic to the Pacific. American shipyards also turned out new fleet carriers such as the Bunker Hill, the Essex, and the Wasp. Joining them were the repaired Hornet and the obsolescent Ranger, several light carriers and close to a dozen escort carriers, giving the Americans the most powerful carrier fleet in history. Japan's situation on the other hand was precarious as she had only launched one new fleet carrier since the war had broken out, the Taiho, and even that ship wouldn't be ready to fight for another year. The US submari