See whales guaranteed or cruise again free! Available daily when in-season, DECEMBER through APRIL, Whales Guaranteed: If you don’t see whales on any of our “WHALE WATCH”-specific trips, come back again 1 more time for free! (Rerides only, no refunds. Reride is on trip of equal or lesser value.). Every December through April, thousands of Humpback whales migrate to the warm waters of Hawaii. Come along see catch these beautiful mammals at their best on our exciting eco-friendly whale watching excursions. Dolphins are likely to be seen, too. Soda, juice and water aboard.