Remember when the biggest animals in the world seemed in danger of vanishing? It was during the 1960s and '70s, when commercial hunting had made many of the great whale species so scarce it looked as if the world would be robbed of an entire dimension of wonder.
It wasn't. If you visit the 'Au'au Channel between the Hawaiian islands of Maui and Lāna'i in winter today, you'll find the ocean grown chunky with titans. Humpback whales that weigh as much as 45 tons (41 metric tons) rise and spout everywhere, roll in spirals, slap the surface with fins or tail flukes. They leap with their tails almost clearing the surface while chins reach 40 feet (12 meters) into the sky, then fall back in a KER-WHOMP! that carries for miles.
Reduced to a few thousand worldwide, humpbacks began to rebound after an international ban on killing them went into effect in the 1960s. A soon-to-be completed three-year census dubbed SPLASH, the largest, most intensive humpback whale survey ever undertaken, could put the North Pacific population alone at more than 10,000 and possibly as many as 25,000.
Half to two-thirds of those whales gather around Hawaii from late November into May, especially here in the channel and other parts of the 1,370-square-mile (3,550 square kilometers) Hawaiian Islands Humpback Whale National Marine Sanctuary. For every humpback drawing cheers from whale-watching boats as it raises a splash in the sunshine, many more lie below.