As many as 10,000 humpback whales visit Hawaiian waters every year from about November through May. These acrobatic, 45-ton marine mammals attract wildlife enthusiasts, but they can pose safety hazards for boaters. Vessel-whale collisions occur every year in Hawai‘i and are a serious risk to boaters and whales. Ocean users are also subject to safety risks when whales surface, breach, or slap their massive tails or flippers. 

Humpback whale season in Hawai‘i generally runs from November through May, although whales may be encountered in limited numbers during other months. The usual peak in humpback abundance occurs from January through March.

Humpback whales congregate in ocean waters less than 600 feet deep throughout the main Hawaiian Islands.  Keep in mind, however, that mariners may also encounter humpback whales at the surface over deeper waters.