"Kids, it will be like Magic Mountain on steroids," he announced to the handful of children in the group, who hopefully had no idea what steroids were.
Stressing that no one with back problems or similar frailties should be coming, that we would all get wet, and that anything we didn't hang on to might go overboard, he led us to the LavaOne, high on its trailer by the boat ramp.
A sturdy, bare-metal catamaran, it was accessed by the evening's first challenge: a stepladder. Scrambling aboard, we meekly sat where instructed by tour guide Jake — "Over 60s to the back! Trust me, you'll thank me later" — except the eager rebel who headed for the front.
"Bull rider, are you?" he was asked scathingly, sending him scuttling.
With admirable efficiency, we were all seated and the boat slid into the water where the promised wild ride began almost immediately. Thumping along over the waves, spray thrown up on both sides and inside too, the kids shrieked with delight while their white-knuckled parents huddled inside their flapping plastic ponchos.
We beat along the coast, where the great lava field of the Kilauea volcano meets the sea in a wall of black rock, punctured by tubes.
Above the roar of the four big outboards and the slamming of hull on sea, Jake shouted the statistics: one of five shield volcanoes on the island, it's been continuously erupting since 1983, and is one of the most active ever known. The spreading lava has taken out more than 200 buildings, burying some more than 20m deep. It reached the ocean in 2012 and has added over 200ha to the Big Island's area.
The temperature of the magma is 1200C. That was easy to believe, as we plunged into a billowing cloud of steam on a suddenly calm sea. Captain Shane manoeuvred the boat so that everyone had a view of the unearthly scene, while Jake dropped a battered tin bucket over the side for us to feel the heat of the water. A pattering on the roof was volcanic debris falling, spat into the sky as the magma met the water with a hiss.
"Put your cameras down," Jake instructed. "Look at this! You'll never see anything like it again."
Next evening, though, we got another angle on Kilauea. We'd spent the day with Steve, who picked us up in the pretty, Napier-like town of Hilo and took us on a Volcano Eco-Adventure tour. There was no actual adventure, but ample volcano and eco, on a drive along the Chain of Craters Road, a walk through the echoing Thurston Lava Tube, and many views of bush, waterfalls and lava fields.
We learned that the smooth lava, shiny when new, and looking as though a herd of giant, and incontinent, cows had passed by, is called in Hawaiian pahoehoe; while the shattered variety is a'a — coincidentally the sound made by anyone attempting to walk across it in bare feet.
The highlight of the tour was The Glow. Arriving at the crater at sunset, we watched as the electric orange of the bubbling, spitting cauldrons of magma got brighter and brighter under an eerily radiant cloud of vapour. We'd seen both ends of Kilauea's eruption, and we were awed.
ON THE MOVE
Two weeks after the writer took this tour, 10 hectares of the lava delta collapsed into the sea, exposing a lava tube out of which a "firehose" of molten rock poured continuously for two weeks before another collapse. More action is expected.
CHECKLIST
Getting there: Hawaiian Airlines flies from Auckland to Hawaii (The Big Island), via Honolulu.
Accommodation: Fairmont Orchid is a beautiful resort on the other side of the island from the tours, but handier for the island's main airport.
Details: Visit seelava.com and discoverhawaiitours.com.
Further information: See gohawaii.com.
