Hawaiian spinner dolphins feed far offshore at night and rest by day in calm, shallow bays such as Kealakekua Bay on the Big Island’s Kona Coast. Guests may see them from the deck of the Hoku Nui. Since 2021, federal law has barred anyone from approaching within 50 yards of them, so the right way to enjoy them is from the boat.
Sea Paradise Hawaii has sailed to Kealakekua Bay from Keauhou Bay since 1985. Here is what our crew wants every guest to know about these remarkable animals.
Why do spinner dolphins come into Kealakekua Bay during the day?
Spinner dolphins come into bays like Kealakekua Bay to rest. According to NOAA Fisheries, they spend about four to five hours a day resting in clear, calm, relatively shallow water, often over a sandy bottom where they can watch for predators approaching.
Their night is spent working. After dark they gather in schools of hundreds and feed on small fish, shrimp and squid about 650 to 1,000 feet below the surface, following prey that rises toward the surface at night.
Fact: by day they split into much smaller groups, sometimes about a dozen animals, to socialize, nurse their young and rest before the next night’s hunt.
Why are they called spinner dolphins?
Spinner dolphins are named for their leaps. They launch out of the water and rotate along the length of their bodies, and NOAA Fisheries notes that a single leap can include several complete spins before they splash back down. It is one of the most memorable sights on the Kona Coast.
Fact: they are slender, small dolphins, 4 to 7 feet long and about 130 to 170 pounds, with males slightly larger than females. NOAA measures adult female Hawaiian spinners at 4.6 to 6.7 feet and adult males at 5.2 to 6.8 feet.
Fact: the population that lives around Hawaiʻi Island is small. NOAA Fisheries estimates the Hawaiʻi Island stock at about 600 animals, and island-associated spinner dolphins stay within about 10 nautical miles of their home island.
Fact: NOAA estimates the Kauaʻi and Niʻihau stock at about 600 animals and the Oʻahu/4-Islands stock at about 300, so every island has its own small, resident population living on its own daily schedule.
What is the 50-yard rule for spinner dolphins in Hawaii?
The 50-yard rule is a federal regulation published by NOAA Fisheries on September 28, 2021, under the Marine Mammal Protection Act. It prohibits anyone from approaching or staying within 50 yards of a Hawaiian spinner dolphin, whether in the water or not, within 2 nautical miles of the main Hawaiian Islands. It applies to people, boats, paddleboards and drones alike, and it also covers designated waters around Lānaʻi, Maui and Kahoʻolawe.
Fact: the rule also bans “leapfrogging,” which means moving a boat or person into the path of oncoming dolphins so they pass close by.
The reason is simple. Dolphins disturbed during their daytime rest cannot recover for the night’s hunt. Watching from a distance protects the very behavior that makes Kealakekua Bay special.
Fact: on the same day in 2021, NOAA Fisheries also published a proposed rule for time-area closures in essential daytime resting habitat for spinner dolphins, including areas on the Big Island.
Fact: spinner dolphins are protected throughout their range under the federal Marine Mammal Protection Act, which makes it illegal to harass, hunt or otherwise “take” them.
How can you see spinner dolphins on a Sea Paradise tour?
Spinner dolphins may be seen from the deck of the Hoku Nui as we sail the Kona Coast or arrive at the World Famous Captain Cook Monument at Kealakekua Bay. They are wild animals, so no sighting can be guaranteed. When they are around, our crew keeps a respectful distance and lets them carry on undisturbed.
In the water, snorkelers explore the reef. They may see the humuhumunukunukuapuaʻa, yellow tang, Moorish idols, parrotfish and butterflyfish, while dolphins, turtles and whales are watched from the boat.
Sea Paradise’s Afternoon Snorkel Tour departs Keauhou Bay at 2:00 PM aboard the Hoku Nui, our 50-foot luxury sailing catamaran. In about three hours, you get a marine naturalist reef briefing, all snorkel gear, light snacks and the sail along the coast. For more on the bay’s protections, see our Kealakekua Bay guide.
Frequently Asked Questions
Can I get in the water with the dolphins at Kealakekua Bay?
No. Since a NOAA rule published on September 28, 2021, it has been illegal to approach within 50 yards of Hawaiian spinner dolphins within 2 nautical miles of the main Hawaiian Islands. Guests may see them from the deck of a boat instead.
Why are there spinner dolphins in Kealakekua Bay?
Spinner dolphins feed offshore at night and come into calm, shallow bays like Kealakekua Bay to rest during the day, often for four to five hours. Resting over a sandy bottom helps them spot predators.
Are there dolphins on Kona snorkel tours?
You may. Spinner dolphins are wild and no sighting is guaranteed, but guests may see them from the deck of the Hoku Nui on Sea Paradise’s Afternoon Snorkel Tour to the World Famous Captain Cook Monument at Kealakekua Bay.
