Butaritari's land defenses were centered around the lagoon shore, near the seaplane base in the central part of the island. There were two tank barrier systems: The west tank barrier extended from the lagoon two-thirds of the way across Butaritari, was 12 to wide and deep, and was protected by one anti-tank gun in a concrete pillbox, six machine gun positions, and 50 rifle pits. The east tank barrier, wide and in depth, stretched from the lagoon across two-thirds of the island and bent westward with log antitank barricades at each end. It was protected by a double apron of barbed wire and an intricate system of gun emplacements and rifle pits.