The lagoon, roughly in size, is shallow—it is at most in depth—and is crossed repeatedly by narrow coral heads and patch reefs. Reef flats generally extend over from the shore—although some sources report them to extend more than from land—and make boat landings perilous except at high tide. There are no natural landings, anchorages, or deep water openings into the lagoon; water which spills into it over shallow channels at high tide is contained within the surrounding reef and remains stable despite ocean tides. Most landings are generally made at a small break in the reef at the northeast corner of South Islet.