June to October is the time when migrating Humpback Whales can be observed in the South Pacific. They wander from the Antarctic to spend the winter in warmer waters. Lots of them head to Tonga, yet a lot stay around Fiji. Winter time is also a period of breeding and birthing. You can see the whales in the waters near Kadavu Island as they spend their mating season and play inside the Great Astrolabe Reef. Swimming with them is an excellent experience, especially when they are in a playful mood, or you can simply watch and feed these giant mammals from aboard.
On your whale watching trip, you could also spot a few Pilot Whales. Unlike the Humpbacks, these reside outside Fiji's reefs and lagoons all year round.