Funafuti is the only port but there is a deep-water berth in the harbour at Nukufetau. The merchant marine fleet consists of two passenger/cargo ships Nivaga III and Manu Folau. These ships carry cargo and passengers between the main atolls and travel between Suva, Fiji and Funafuti 3 to 4 times a year. The Nivaga III and Manu Folau provide round trip visits to the outer islands every three or four weeks. The Manu Folau is a 50-metre vessel that was a gift from Japan to the people of Tuvalu. In 2015 the United Nations Development Program (UNDP) assisted the government of Tuvalu to acquire MV Talamoana, a 30-metre vessel that will be used to implement Tuvalu's National Adaptation Programme of Action (NAPA) to transport government officials and project personnel to the outer islands. In 2015 the Nivaga III was donated by the government of Japan; it replaced the Nivaga II, which had serviced Tuvalu from 1989.

Answer this question, if possible (if impossible, reply "unanswerable"): What do Tuvalu's merchant fleet carry?
cargo and passengers