Cubadak island is located in Indonesia , West Sumatra.

Padang, the capital of West Sumatra, has an international airport that offers daily flights from Jakarta, Medan or Kuala Lumpur. From Singapore ferries rally the Indonesian island of Batam every hour and there are daily flights from there to Padang.
From Europe it is very easy to fly direct to any of these capital cities :
major companies are Malaysian Airlines, Singapore Airlines, KLM, Air France or Lufthansa, but there are many other options as via Dubai with Emirates Airlines…
The transfer from the airport to downtown Padang takes about 30 minutes.