Best Adventure Vacations: Top 5 Islands

1. Snorkeling in Jellyfish Lake

EIL MALK, PALAU: Islands are wilder and weirder than continents. They're harder to get to, harder to spoil. Count me in. My best natural experiences take place on islands. And for me the challenge of getting there heightens the experience. True, I complain as loudly as anyone about security lines, tiny middle seats and overnight flights. But when I slip into Dominica's cool waters on the way to an underwater volcano or compete with grizzlies for salmon amid the evergreens of British Columbia, the thrill is doubled because I've earned it. Some of these five outdoor adventures can be reached in hours; some take days. All of them, for me, were eye-opening and jaw-dropping. And none more so than snorkeling in Jellyfish Lake on Palau's Eil Malk Island.

Millions of golden jellyfish floated around me in the dark green water like stars in a miniature galaxy. The jellies follow the sun on a daily migration, just as they have since the last ice age sealed this marine lake off from the rest of the South Pacific. "Be very careful around them," the guide from Fish 'n Fins said. "Swim gently." He wasn't worried that the jellies would sting us — their venomous defenses have been dampened over time in this aquatic Shangri-la. Rather he worried we might damage their delicate forms with a careless kick. So I floated through those strange glowing stars, careful not to disturb an underwater universe that has existed unchanged for more than 12,000 years.

2. Fly-Fishing with Grizzlies

BRITISH COLUMBIA: The autumn sun danced on the river; snowmelt swirled around my waders. A mellow day of fly-fishing was unfolding in British Columbia's Great Bear Rainforest — and then the grizzly bear charged. Dan Caldwell, my guide from the King Pacific Lodge, pulled out his "bear popper," a kind of anti-grizzly hand grenade. "Get your bear spray out."

Dan had convinced me to take this all-day adventure after I announced that fishing was dull. To prove me wrong, we'd flown to this unnamed river in the lodge's private helicopter, doors off and the smell of the ancient pines flooding the cabin. We'd been catching and releasing trophy-size coho salmon for hours — until the bear arrived.

The grizzly closed. I fumbled with the spray. Two hundred yards, 100, 50, 10. Then the bear stopped. He snorted, shook his head and turned around to join his buddy. Dan laughed. "Still think fly-fishing is boring?"

3. Sea Kayaking the Na Pali Coast

KAUAI, HAWAIIAN ISLANDS: "If you're scared or seasick, this is the point of no return," said Steve Preibisius, our guide from Kayak Kauai. A half-dozen of us novice sea kayakers were floating in the swell off Kauai's Ke'e Beach. I was scared and seasick, but before I could confess, Steve gave a hoot, dug his paddle into the green water, and we were off on what paddlers affectionately call "the Mount Everest of sea-kayaking trips."

The sheer beauty of this roadless wilderness cured my queasiness. We ducked into misty grottoes. We surfed our kayaks on the 12-foot rollers coming in from Alaska. We cooled off under a waterfall and ate lunch on a beach beside a snoring monk seal while the staggering cliffs rose nearly a mile above us. By the time we slid our kayaks ashore at Polihale State Park eight hours and 16 miles later, my cheeks ached from smiling so much.

4. Swimming Inside a Volcano

CHAMPAGNE BEACH, DOMINICA: "I'm taking you swimming inside an active volcano," Derek Perryman said as we jumped into Dominica's most unusual snorkeling spot. I'd spent a week diving the island's lush reefs with Derek, the owner of Castle Comfort Lodge, and on one of our surface breaks he brought me to the waters off Champagne Beach for an experience I'd never forget.

The water was refreshingly cool on the surface, but when we dove down 20 feet to the stony seafloor, I could feel the soft tickle of heated bubbles percolating out of a field of rusty orange boulders. All around us curtains of silver bubbles rose, a relief valve of sorts on an island with the densest concentration of volcanoes in the world.

Derek showed me a dive computer that displayed the ambient 82-degree water temperature. Then he stuck it into a bubbling vent. Within seconds it climbed to 120 degrees. That's hotter than most people like their champagne, but in Dominica it was still the coolest drink around.

5. Biking Central Otago

SOUTH ISLAND, NEW ZEALAND: For a few thrilling minutes, the sheep-flecked sides of the Poolburn Gorge in Central Otago vanished as I hurtled headlong into a train tunnel on my mountain bike. This was my second tunnel of the day, and it curved, so there was no proverbial light at the end of it. Overwhelmed by darkness, I hopped off my bike, flipped on a flashlight and began walking.

It was early winter, and I was riding the newly opened Central Otago Rail Trail, a century-old railway repurposed as a national biking and walking trail. Trail Journeys, which offers guided and independent tours, had hooked me up with a bike, flashlight and picnic lunch, and shuttled me out to spend an afternoon pedaling from Auripo Road to the village of Lauder, an easy seven miles. Many summer riders take three days to travel the entire 93-mile-long trail, overnighting at country inns.

My heart leapt for a second when another light came bobbing toward me through the black tunnel. A ghost train? Happily not. Just another rider out on the rails.