The 2d Marines was now relieved and the 6th Marines moved into the attack along the coast while the 8th Marines took up the advance inland. Naval gunfire support, spotted by naval officers ashore, improved measurably. On the 15th, the Americans, both Army and Marine, reached the initial corps objective. In the Marine attack zone, 600 Japanese were dead. The 8th Marines was essentially pinched out of the front lines by a narrowing attack corridor as the inland mountains and hills pressed closer to the coastal trail.