Micronesia
Best overall months to dive: Jan, Feb, Mar, Apr, Dec
The Federated States of Micronesia spread across the western Pacific north of the equator, made up of four states: Yap, Chuuk, Pohnpei and Kosrae. For divers the headline is Chuuk (formerly Truk), whose lagoon holds the sunken Japanese fleet from the WWII air raid of February 1944. Yap is known separately for manta rays and Pohnpei and Kosrae for reef diving, but Truk Lagoon is what puts Micronesia on the dive map. Access is long: nearly all traffic routes through Guam on United's island-hopper.