It was 6 a.m., and the Gulden Leeuw, a three-masted topsail schooner, was 100 miles off the coast of Senegal when the storm arrived.

Before she could realize what was happening, Madeline Henderson watched as the helm of the 230-foot ship began to spin out of control.

Rain pelted Henderson’s face. A bolt of lightning lit up the sky. Dolphins leapt from the water. The vessel began to keel, and four others scrambled to help her wrest control of the wheel.

Although she’s too young to vote or buy cigarettes, Henderson, 17, of Brunswick was simply doing her job that night, one of about 40 students from around the world who chose to bypass traditional schooling in favor of a year studying at sea. They take turns on watch, navigation and helm duty, living the seafarer’s life.

“My favorite time is when there are storms,” she said. “That’s when it gets really interesting.”

By January, after having traveled more than 10,000 nautical miles in her first semester and crossing the Atlantic twice, Henderson was hungry for more.

The Nova Scotia-based program, Class Afloat, accepts high school and college-level students for semester or yearlong experiences, costing up to $57,000 a year for American students.

In an interview during a brief stint stateside, Henderson said she wanted to do something different for her senior year. At first trepidatious, Henderson said now she is glad to have dispensed with the traditional school schedule.

Madeline Henderson climbs the rigging aboard the Gulden Leeuw, the three-masted ship she’s sailing on for her senior year of high school with the Nova Scotia-based Class Afloat program.

Madeline Henderson climbs the rigging aboard the Gulden Leeuw, the three-masted ship she’s sailing on for her senior year of high school with the Nova Scotia-based Class Afloat program.

Instead of rising from a plush bed at home with her family, each day Henderson emerges from her bunk, sometimes weary from a night on watch, to a far more encompassing routine.

After breakfast at 7 and an hour of compulsory cleaning duty at 8, the ship’s students assemble on deck for a head count and morning announcements, before breaking out into classes from 9 a.m. to 6 p.m.

The students catch short naps or do homework between activities.

With no Internet or television, the regimen recalls a simpler life. Henderson didn’t even miss her cellphone, she said.

Adjusting to life at sea took time, however.

The ship sails from Amsterdam, and after teary dockside goodbyes, the neophyte sailors were immediately put to work, Henderson said.

“It was really weird just not knowing anybody,” she said. “The first couple weeks were kinda awkward.”

After a jaunt down the European coast to Portugal, the young mariners continued to Morocco and Senegal, before setting off on their first Atlantic crossing.

It was 20 days without sight of land or ship, before the group landed in Brazil.

Along the way, they experienced some of the joys and inconveniences of living in close quarters.

After experiencing a breakdown of the machine that converts seawater into potable water, the 60 people aboard had to limit their showers to 60 seconds each.

When that failed, it was down to an even simpler technique.

“We had to take bucket showers on the deck,” Henderson said. “It was really cold in the South Atlantic, so we didn’t want to do that, either. We all got kind of nasty.”

The quality of food aboard the ship worked on a sliding scale of sorts. The longer they stayed at sea, the fewer ingredients remained.

“By the end you’re just eating beans. Bean burgers, bean casserole. Mixing beans into omelets. Beans with everything.”

After the long sail, Henderson met up in Buenos Aires with her parents, who rented an apartment.

Her mother, Elizabeth, recalled with amusement watching her nearly adult daughter’s face light up for the least expected reason.

“She was so excited to see a couch,” Elizabeth Henderson said.

Now the teenager is off once again, expecting to cover another 10,000 nautical miles before graduating in the spring.