Hawaiian spinner dolphin

Spinner dolphins use the calm, sheltered waters off Lanai's leeward coast as their primary daytime resting habitat in Maui County, gathering in groups of 50 to 200 animals after nightly offshore feeding forays. At First Cathedral, small groups enter the cave's tunnel entrances in the early morning, their echolocation clicks audible throughout the chamber in a way that is rarely experienced anywhere else in Hawaii. Federal marine mammal regulations prohibit swimmers from actively pursuing or intercepting spinner dolphin resting groups — but dolphins at this site are habituated to dive boats and sometimes approach in genuine curiosity.