After four days of steaming west toward the Mariana Islands, the ships of Task Force 58 finally came into carrier plane range of Guam. On June 11 and 12, they launched wave after wave of fighter and bomber planes, hitting targets up and down the island. Attacks against enemy bases on Saipan and Tinian on June 13 triggered the implementation by the Japanese of their defensive strategy A-GO, the unleashing of the bulk of their warships in an all-out attack on the American Fleet.
On June 14, while the Boston and the ships of task groups 58.1 and 58.4 steamed north to raid the airbases on Iwo and Chichi Jima, The Japanese Combined Fleet began steaming north and east into the Philippines en route to engage the Americans off the Marianas.
After attacking the Jimas in bad weather on the 15th and 16th, the Americans were ordered to meet up with the rest of the fleet east of Saipan and Tinian. On the morning of June 18, all four task groups, and an additional “Battle Line” group of battleships and cruisers, formed up into a large Battle Formation. The Japanese Fleet was headed their way!
On June 19, at first light began the three-day naval battle known as the Battle of the Philippine Sea. When the sun set on the 21st, the balance of power in the Pacific had flipped from Japanese Supremacy to American Naval Superiority.
I will spend a little time ASAP talking about the action of June 19-21. It is an incredible story, and it includes the Marianas Turkey Shoot and the reduction of one third of the Japanese Fleet.