A Japanese vessel was partly submerged off Guadalcanal in 1942 after being hit by American forces. The battle helped turn the Pacific war in favor of the United States and its allies. Some 7,000 Japanese were reported missing on Guadalcanal.Credit...US Navy/Getty Images GUADALCANAL, Solomon Islands — Using a trowel to dig into the shadowy floor of the rain forest, pausing only to wipe away sweat a