“When I look into the doorway of a cave, I see the opportunity to view something that nobody’s ever seen before, the kind of experience that nobody’s ever experienced before,” she says, adding that she then shares that experience with the world.

And that’s exactly what she did at The Royal Canadian Geographical Society’s 2014 spring speakers series on April 30. The 49-year-old thrilled the sold-out crowd at the Canada Aviation and Space Museum in Ottawa with tales of her many underwater adventures and deadly pursuits.

“We know more about space than we do our undersea world, and there’s so much for us to learn from these environments.”

As a child, Heinerth got her first taste of exploration through TV, watching Jacques Cousteau travel underwater and Neil Armstrong walk on the moon.

“I wanted to be an astronaut,” she says, “but a young girl at that time really wasn’t encouraged to follow that path. It wasn’t something that people thought was possible. But secretly, I always held that desire to become a diver. I didn’t get the opportunity to chase that dream until I was in university.”

Heinerth obtained a Bachelor of Fine Arts at York University in Toronto and had a successful career in graphic design. But at night and on weekends, she travelled to Tobermory, Ont. to scuba dive or teach others to dive.

Taking the first of many brave steps, Heinerth eventually chose to give up her career, sell her business and all her personal belongings and move to the Cayman Islands to pursue scuba diving full-time.

“I knew I needed to find a way to get out of the four walls of my office and blend my creative interests and background with my desire to be underwater,” she says.

With hard work and persistence, she was not only successful in becoming a professional scuba diver, but also conquered the roles of filmmaker, writer, underwater photographer and creator of the We Are Water project. She’s also been awarded the Sir Christopher Ondaatje Medal for Exploration.

And now, she can add RCGS speaker series presenter to that list.

Much of Heinerth’s presentation focused on her experience making Ice Island, a film chronicling her team’s exploration of caves inside an Antarctic iceberg. Originally, Heinerth was hoping to follow in the footsteps of Ernest Shackleton, who explored Antarctica 100 years ago. But as she was preparing for the journey, an iceberg the size of Jamaica calved off from Antarctica’s Ross Ice Shelf, becoming the largest iceberg in recorded history.

“When it happened, there were chills down my spine,” she says. “I knew immediately that we were going to go there and intercept this iceberg.”

So began a 60-day journey into freezing, ice-packed waters to find out what lay within the iceberg.

What Heinerth and her team found were fractures, crevasses and caves within the iceberg that allowed them to scuba dive along orange, yellow and red sea floors covered by ice archways glowing blue and white in the light. Despite the cold, inhospitable environment, the iceberg was teeming with life.

“We had thousands of these amphipods crawling around like giant cockroaches, falling off the ceiling and landing on us, crawling around and mating,” she says. “It was just a riot of life. Before that, nobody had ever seen it.” She also notes the team found a new species of killer whales near the iceberg.