We've been scrabbling downhill over rocks for an hour, eager to reach the ocean at the bottom of the track. Waiting for us, we are told, is beautiful life underwater - and an emotional tale of death.
Our path winds through green shoots taller than our heads. The air is hot and heavy with moisture, insects buzz around my face as snails crawl slowly across the damp soil at my feet. I have to concentrate not to step on them but I want to be looking up, catching the Pacific blue through the bushes. It all feels so alive.
Looking over us from behind is a landscape of total contrast: grey volcanic rock, so buckled and clumped it looks, even from up close, like a field of hard, dirty mud. Wasted and dead. Gently it slopes uphill towards the island's interior, where, way up high beyond the veil of fog, sits the world's most active volcano Kilauea, bubbling and crackling away.
We visit Hawaii's Big Island in April, before Kilauea started shooting boulders into the air and sending lava though backyards and streets. But even then, Kilauea was a volatile force of nature, venting her blistering lifeblood down to the ocean, as she's done every day for over 30 years.
The Big Island's youth and evolving nature has created a landscape that is dramatically varied, more so than Hawaii's other islands and probably more so than almost anywhere on earth. Aside from a bubbling volcano, there are wintry snowscapes, native tropical rainforests, macadamia nut orchards and coffee plantations, undeveloped coastlines, beaches of white sand and black rock.
The world's tallest mountain, Mauna Kea, strikes up from the sea, standing at over 10,000 metres measured from its undersea base (4,207 metres above sea level), while under the ocean some of the most stunning tropical fish I've ever seen explore the island's underwater coral and coves.
It's this ocean world that we're keen to discover today. But while Kealakekua Bay on the eastern Kona Coast may offer some of the best snorkelling in Hawaii, it's not just a pretty place.
Like the island itself, it's shrouded in drama. Captain James Cook was killed here by natives during his third exploratory voyage in the Pacific.
Relations between Cook, his crew and the Hawaiians was at first pleasant - Cook and his men offered gifts in peace and they had learned some Tahitian some months earlier, which was close enough to the Hawaiian dialect that the two sides could communicate. But resentment grew, with the crew accusing natives of pilfering their supplies. The story goes that Cook tried to kidnap Hawaiian chief Kalaniopu'u in order to reclaim a cutter stolen from one of this ships. Cook was then killed by the mob.
The remains of Kalaniopu'u's village are still here, a collection of stones standing eerily by the rocky water's edge. It's poignant to imagine the battles and torments that went on here so long ago, especially when we see bullet holes in the cliffs supposedly fired by Cook's men.
Down by the bay, a tall white monument erected by Cook's fellow Brits pays tribute to the "great circumnavigator .. who discovered these islands on 10th January 1778 and fell near this spot on 14th February 1779."
Kealakekua Bay is quite hard to reach (the 5km bush track or boat is the only way). Once here, it feels peaceful and reflective, in sharp contrast with its violent history. A handful of colourful hippies, travellers and students lie on the rocks and grass, drying off from a snorkel, while I stare out to sea.
Cook couldn't swim, which was not usual back then; many seafarers feared immersion in water could bring on disease and death - a mistrust for the ocean they also so loved and respected. If Cook could have swum, maybe he would have found safety that day.
With this in mind we slip into the warm, turquoise water - Cook's final resting place. Pretty, bright fish dart and glide among the coral gardens.
What a beautiful place to die.
Death is also on our minds when we visit the remains of a village on the other side of the bay. In centuries past, breaking sacred law, or kapu - imagine a woman eating with a man, or catching a fish out of season - resulted in the ultimate punishment. Your only hope of survival was to find your way to this Place of Refuge, now known as Pu'uhonua O Honaunau, where you could be absolved by a priest.
Wooden statues of menacing Hawaiian Gods look out over an austere black beach, their sinister expressions etched in history, alerting people of the mana, or spiritual power, of this place.
The village became less important after the death in 1819 of Kamehameha I, the great king who united the Hawaiian islands. During the mourning period, two of his wives and his son defied kapu by eating together, an action that prompted the collapse of the kapu system, later accelerated by the arrival of Christian missionaries, Americans and Europeans.
Pu'uhonua lost its reason for being in the subsequent decades, its mana of no use in the western world, but today it lives on as a state park and a reminder of the past.
From the death of Kamehameha and kapu came life.
Kamehameha also saw his end here on the Kona Coast at Kailua-Kona, now a tourist hub of restaurants, bars, surf shops and shave ice shacks. People have carved a life out of the dead black geothermal vomit, and by living here really live on a razor's edge, as they're discovering now.
We drive back to our own magnificent sanctuary, Hilton Waikoloa Village, along the highway that loops the island on the coast. It's another chance to ponder the dramatic landscape. Skies and colours change quickly here, as trade winds blow clouds in during the afternoon. We never see the mountains, which sit under their persistent misty veil.
Spreading downhill from the summits, the black lava fields lie barren and choked. But there are tiny flashes of colour amid the volcanic cinder - small crosses covered in bright flowers; human death along the highway that the volcano didn't claim. A testament to life and love that goes on.
Here, nature is powerful and persistent. As Kilauea simmers up high, green pushes out far below. From lava flows just a few months old, baby ferns are poking through.
IF YOU GO
GETTING THERE: For flights to Big Island's Kona Airport via Honolulu, and travel all over the Hawaiian archipelago, Hawaiian Airlines is your one-stop shop. For more, www.hawaiianairlines.com.au
The entrance to the Kealakekua Bay hike is 30 minutes' drive from Kailua-Kona; there's no public transport. Kealakekua Bay is also accessible by kayak. Aloha Kayak is one of the better operators (www.alohakayak.com)
You can't landfill rented kayaks at Kelakekua Bay, except by permit. This is a measure to protect the bay from increased human impact.
STAYING THERE: Hilton Waikoloa Village, on the north end of the Kona Coast, is a magnificent hotel with it's own private beach and water parks. For more, www3.hilton.com. Rooms from $US250 ($A330).
The writer travelled as a guest of Hilton and Hawaiian Airlines.