Rugged cruise to an active South Pacific volcano

White Island, a cruise ship shore excursion to an active volcano off the north coast of New Zealand, is not a trip for the queasy or careful.

At least one American expert on volcanic activity says that White Island is highly dangerous. Maybe that’s why some cruise passengers choose a flying tour offered by several ships, including those of Crystal Cruises and Seabourn, and excursion broker Viator.com.

This cruise column is not a recommendation to fly or boat from Whakatane, near New Zealand’s port of Tauranga, to land on White Island. It is a report from a traveler who made the sea journey, which was the strangest and most exciting tour of my life.

White Island, which was formed by volcanic eruptions, is a world of gaseous steam and serious acid. The ground shakes, the result of the Ring of Fire that burns below the rim of the basin of the Pacific Ocean.

Though 15,000 to 20,000 people arrive at White Island by boat every year, at first I felt foolish, wondering why a rational person would choose to saunter through a bubbling minefield that could explode at any time. Then, I felt the exhilaration shared by volcano explorers through the centuries, being the rare witnesses to the natural power and fury that usually hide from our view beneath the surface of the earth. Besides, my will was up to date.

The island is like no other tourist attraction. Handrails and fences do not exist. Travelers don gas masks and hardhats for guided tours of more than an hour over rugged terrain where no one takes a step without asking whether it is safe to move forward, back, left or right.

“You could walk into a hole in the earth,” said my guide, Hayden, “and be steamed to death while the acid stripped your hide to the bone.”

Our group of about a dozen kept close to the guide. From the moment we slid out of a skiff onto a small dock, Hayden had our full attention. Most injuries on White Island, he said, are sprained ankles, as travelers are captivated by picture opportunities and miss the loose rocks that litter the unmarked and unrecognizable trails.

A bright blue sky provided the backdrop for a landscape of craggy, corroded ridges of scorched earth, porous rock streaked with yellow sulfur, and chimneys of sulfur crust rising from an unstable floor, until the next rain forces them to collapse.

At the bottom of slopes around us, white blasts of steam billowed from hidden holes. Closer to the steam, we grabbed our gas masks so we could breathe without a burn from water vapor mixed with carbon dioxide, sulfur dioxide, and who knows what else. We sucked on hard candy to reduce the urge to cough.

Hayden led us to the edge of a lake bubbling with acid. “It’s as active as you’ll get,” he said. “Step where you are told not to, and you could be disfigured for life — if we could pull you back to safety.”

Earthquakes shake the island most days. Occasionally they are so strong that the tour boat turns around and heads back to port. A travel writing colleague, who twice has journeyed halfway around the world from the United States with a plan to see White Island, has yet to get there; twice the last leg of the trip was canceled due to weather or island activity.

Erik Klemetti, an assistant professor of Geosciences at Denison University in Granville, Ohio, is the volcano expert who worries about the potential dangers to travelers at White Island.

“I have trouble with White Island as a tourist activity,” Klemetti said during a recent interview. “It’s not an amusement park attraction. It’s a gaping hole in the surface of the earth that could explode catastrophically and unexpectedly.” Klemetti provides a webcam from White Island on his blog, www.wired.com/wiredscience/eruptions.

If you choose to go on a boat tour, either from a cruise ship or on your own, be aware that the voyage from the mainland may be rough and rolling. On my tour, guides recommended pills to ward off seasickness, and a seaman handed out bags for the ill on both legs of the two-hour ride.

After, plan for an evening of recuperation and easy breathing.

David Molyneaux writes monthly about cruising. He is editor of TheTravelMavens.com