Under a law designed to protect the humpback whale, Hawaii is banning jet skis, parasailing and other high-speed operations west and south of Maui until May 15.

The law took effect Dec. 15. The five-month winter season is when humpbacks swim more than 3,000 miles from Alaska to Maui to give birth and nurse their calves. Humpback whales have been on the endangered species list since 1966.