For nearly two years "Pathfinder" operated along the dangerous New Guinea-New Britain-Solomon Islands areas as allied land-air-sea forces fought to break the Japanese grip on the area. An isolated reef, an uncharted harbor, a lonely stretch of enemy held coastline—each presented a different problem. At Bougainville, Treasury Island, Green Island, Emirau and Guam, advance "Pathfinder" parties were sent ashore under the noses of the Japanese to work in close cooperation with Allied amphibious elements in laying out harbor charts or surveying inland channels.