Cook Islands

The Cook Islands is a nation in the South Pacific, with political links to New Zealand. Its 15 islands are scattered over a vast area. The largest island, Rarotonga.

The only one operator is BlueSky.

You can buy sim card in many locations, no registration needed. You will be able to buy sim right in baggage area of Rarotonga airport, before customs.
 * to check balance, dial *888#