 While a few offshore anchorage spots are marked on maps, Jarvis island has no ports or harbors, and swift currents are a hazard.There is a boat landing area in the middle of the western shoreline near a crumbling day beacon, and another near the southwest corner of the island.The center of Jarvis island is a dried lagoon where deep guano deposits accumulated, which were mined for about 20 years during the nineteenth century.