Starting from the month of November up to mid-April, humpback whales travel to Hawaii to mate and give birth; it is in Maui where most of these whales are found.
The shallow seas off Maui's south and western shores as well as the warm water temperature and lack of predators makes Maui one of the world's top whalewatch spots.
If you are in Maui during the "whale" season, you should not miss the opportunity of going whalewatching. There are whalewatch cruises available but for one who does not have the megabucks to shell out, you can watch a whale breaching, pec slapping or spy hopping from the shore, for free, of course. Just arm yourself with a pair of binoculars and look for a good vantage point. The historic port town of Lahaina has a lot of them.
One of the popular free whale watching places is the Papawai Scenic Lookout. A member of a non-profit whale foundation is even on hand to answer questions and lend you binoculars.