Kauai

Step back in time to a seemingly prehistoric environment while diving off the island of Kauai. The oldest in the Hawaiian chain, the Garden Isle is a heaven of thick green rainforests, towering red sea cliffs, deserted golden beaches and the Grand Canyon of the Pacific, Waimea Canyon. Underwater, the reefs have had more time to develop rich ecosystems, which is a strong draw for savvy divers.

“Kauai is not blessed with colorful soft corals, but we make up for it in diversity of marine life,” says Marvin Otsuji of Seasport Divers. “The endangered Hawaiian green sea turtle is now once again abundant and seen on almost every dive, and during the winter months, humpback whales, spotted eagle rays and manta rays are easily spotted while transiting between sites.”

Related Reading: A Land-and-Sea Tour of Hawaii's Big Island

At signature south shore sites such as Koloa Landing, Stone House and Brennecke’s Ledge, divers will find dramatic volcanic features populated by bright tropical fish, plentiful green sea turtles, whitetip sharks, giant trevally and schools of colorful blue-striped snapper — not to mention macro critters from nudibranchs to frogfish. At Sheraton Caves, a giant cavern is a safe haven for napping turtles, and literally dozens of dozing honu can be found here on the best days. Other noteworthy sites on the east and north coasts, including Tunnels Reef, can be accessed during the calm, flat summer months. But the true gem of Kauai diving is Niihau, the Forbidden Isle.

“Niihau is one of the last untouched frontiers in the Hawaii Islands, and the diversity of the marine life and the geography is unlike any other,” says Otsuji, who has been exploring the reefs of Kauai and Niihau for nearly four decades. The westernmost island in the chain, which is about 17 miles from Kauai across the Kaulakahi Channel, is privately owned and off-limits to tourists.

Fortunately, Otsuji is able to bring his guests here to experience the most pristine diving in Hawaii at hallowed reefs and walls such as Vertical Awareness, Niihau Arches, Stairway to Heaven and Keyway. Because of the island’s isolation, big animals abound underwater here, including several species of pelagic sharks, thick schools of giant trevally, and the elusive, endangered Hawaiian monk seal.

“My best dive was off Five Fathom Pinnacle,” Otsuji recalls. “Everything that Hawaii has to offer was there — I was surrounded by 200 gray reef sharks, watching tuna feed on a school of baitfish, while listening to the song of a Hawaiian humpback whale.”

Tales like this have kept Niihau and neighboring Kauai on the minds of intrepid divers in search of exotic adventures — and keep them coming back for more.

seasportdivers.com

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The Na Pali coast of Kauai is one of the most dramatic — and dangerous — coastlines in all of the Pacific. And the daunting Kalalau Trail hugs its rugged back along 11 miles of muddy paths where one wrong step could be your last. For the truly adventurous, a permit from the park rangers lets you hike the entire way to Kalalau Beach, where a “Fantasy Island” waterfall and starlit night skies await. For the rest of us, a 4-mile round trip gets you to Hanakapiai Beach, where a cool freshwater stream will refuel you for the return trip.

kalalautrail.com

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