Whale Watching Tours in Hilo Bay. During Hawaii whale season the calm protected waters of Hilo Bay are frequented by Humpback Whales ideal for a family friendly Big Island Whale Watching adventure. Guaranteed sightings on every Hawaii whale watching tour or you come again FREE. As the only US Coast Guard rated boat in Hilo our Whale Watching cruises ensure you an intimate whale watching excursion. Whale Watching, Waterfalls & Wildlife are all included on this Big Island tour.