The first confirmed sighting this season of a humpback whale in the Hawaiian Islands Humpback Whale National Marine Sanctuary was made Monday off Hawaii island, federal officials reported.

Sea Quest tour captain Tony Roensch witnessed Monday two tail slaps from a humpback whale yearling in Honaunau Bay, the first confirmed whale sighting in the sanctuary this season, the National Oceanic and Atmospheric Administration said Wednesday.

Humpback whale season in Hawaii generally runs from November through May, although whales may be encountered in limited numbers during other months. As many as 12,000 humpback whales winter in Hawaiian waters each year.

Endangered humpback whales are protected in Hawai’i. Federal regulations prohibit approaching within 100 yards of whales when on the water, and 1,000 feet when operating an aircraft. These and other regulations apply to all ocean users, including vessel operators, kayakers, paddle boarders, windsurfers, swimmers and divers throughout the Hawaiian Islands.

“It’s important for everyone to be extra vigilant during whale season, for their own safety and the protection of these magnificent animals,” Paul Wong, operations coordinator for the Hawaiian Islands Humpback Whale National Marine Sanctuary, said in a news release.

People who come across an injured or entangled marine mammal are asked to maintain a safe distance and call the NOAA Marine Mammal Hotline at 1-888-256-9840 immediately, or the U.S. Coast Guard on channel 16. If reporting a suspected approach zone violation, please call the NOAA Fisheries Enforcement Hotline at 1-800-853-1964. Additional guidelines and safety tips can be found at http://hawaiihumpbackwhale.noaa.gov.