Nanumanga has no lagoon to anchor in, only a fringing reef around the entire island. Cargo and passenger boats from Funafuti stand off the reef on the west side and offload by aluminium dinghy through a narrow passage in the coral. In rough seas this transfer is genuinely dangerous; arrivals are sometimes called off and the ship simply sails on to the next island.
For visitors the reef passage is the first and last sight of Nanumanga, and worth understanding before you commit to landing. Walking out at low tide gives a view back across the reef flat to the village and the deepwater drop-off where ocean fish congregate. The waters just outside the passage are an important traditional fishing ground.