page_title: Hatohobei
section_title: Helen Reef
hierarchical_section_title: Hatohobei / Helen Reef
caption_attribution_description: English: Tern rookery on Helen Island (Helen Reef), Palau
context_page_description: Tobi, or Hatohobei, also ハトホベイ州, is the southernmost of Palau's sixteen states, consisting of Tobi Island and Helen Reef. The total land area is about 0.88 km². The population was 80 in 1962, 51 in 1995, 23 in 2000, and 25 in 2015. Tobian, English and Sonsorolese are the official languages of Hatohobei State.
  It is the least populous first-level administrative subdivision in the world.
  The individual islands of Hatohobei, together with the islands of the state of Sonsorol, form the Southwest Islands of Palau.
context_section_description: Helen or Helens Reef (Hotsarihie), about 70 km east of Tobi Island, is a largely submerged atoll, with just one islet (Helen Island). The atoll is 25 km long and nearly 10 km wide, with a lagoon area of 103 km² and a total area including reef flat of 163 km². A channel leads into the lagoon from near the middle of the western side of the reef. Immediately south of the channel is Round Rock, which dries. The lagoon has about 85 patch and pinnacle Reefs.
  When the tide is falling, the water flows out of the lagoon and over the reef in all directions until the reef is uncovered, and then flows out through the channel on the western side. On the rising tide, a reverse effect is noted. Only few parts of the reef completely dry.
  Helen Island, the only island of the reef, is located near its northern tip. It is tiny in comparison to Helen Reef, about 20 to 40 m wide and 400 m long, or about 0.03 km² of land area. The densely wooded island sits atop a sand dune, which is 0.25 km² in extent and which is moving southeast, falling into the lagoon, at a rate 3 to 4 m per year. The island is uninhabited except for a marine ranger station of Hatohobei State, which was established in the early 1990s on the eastern side of the island, to guard the reef against foreign poachers. The station is permanently occupied by a staff of three.
  Helen island was discovered by the Spanish naval officer Felipe Tompson in 1773, who charted it as San Felix shoal.
caption: Tern rookery on Helen Island
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