Shipwrecks, dangerous caves and exploding icebergs are all in a day’s work for Jill Heinerth.

The 50-year-old diver, underwater photographer and film-maker has spent decades exploring some of the world’s most dangerous waters.

She’ll be giving a lecture about some of her experiences tomorrow evening at the Bermuda Underwater Exploration Institute.

Bermuda has been one of her tamer dive locations.

“I’ve visited Bermuda many times,” she said. “Bermuda is actually one of the biology hot spots for cave-adapted life. There is so much that we don’t know yet.

“We find tiny creatures that have never been documented before in Bermuda caves. Sometimes they are endemic to a single cave. Sometimes they are endemic to a single room within a cave.”

Her most dangerous dive was a cave in an Antarctic iceberg 15 years ago. The Connecticut-sized iceberg was one of the largest on record and broke off the Ross Ice Shelf in 2000. No one had ever dived inside an iceberg like this before Ms Heinerth came along.

“The biggest obstacle to the dive was Mother Nature herself which sent extreme currents ripping through the iceberg at unexpected moments,” said Ms Heinerth. “During that project we had one dive where a doorway caved and sealed after we went through.

“We had tremendous currents that pinned us down in the iceberg and swept us through a tunnel disposing us on the other side.”

Using high-tech diving equipment called rebreathers, Ms Heinerth and her team were able to stay underwater for three hours at a time to observe the biology in the inner iceberg.

“Being inside an iceberg was a bit like being in outer space,” she said.

“The inside of an iceberg is loud. It creaks and groans and there is the constant sound of cracking.”

In fact, the entire iceberg chunk exploded just a few minutes after the team was safely back on the ship.

“It broke into a million pieces,” said Ms Heinerth.

“It turned into an endless sea of brash ice.

“If we’d been in the iceberg when that happened we certainly would have died.”

This week Ms Heinerth will also be teaching rebreathing techniques to scientists at the Bermuda Institute of Ocean Sciences (BIOS).

She has written many books on diving techniques and has become a pioneer in rebreather diving, still not used by the majority of divers because of the level of training needed.

“It is still a very young technology,” she said. “It takes a lot of training.

“There are no bubbles so it is a silent thing.

“It allows you to have deeper dives with long durations underwater.

“There are also no bubbles to scare away marine life, the way there is with scuba gear. It is a great tool for scientists.”

Her interest in diving started when she was a child watching documentaries about famed French ocean explorer Jacques Cousteau.

She grew up in Toronto, Canada and learnt to dive in Fathom Five National Marine Park off Tobermory, Ontario, Canada, a shipwreck magnet.

She did not immediately think of diving as a career, and studied fine arts in university. She started off running an advertising agency in Toronto, but missed being outdoors.

“I was teaching scuba nights and weekends,” she said.

“I eventually sold the advertising business in an attempt to combine my creative passions with my underwater love.

“That is how I started doing underwater photography.”

Slowly, she meshed her career into a hybrid of photography, writing, film-making and dive training.

“It gives me a wonderful variety,” she said.

“But it’s not an easy career. It is very physical. I am outdoors and active most days.

“It is definitely hard on my husband as I have long absences from home.

“He also has to worry about dangerous expeditions I am involved in.”

Still, she gets up every morning to do what she loves.

“I get involved in a lot of other people’s exciting scientific work,” she said.

“There is no replacement for that wonderful opportunity.”

• Her talk The Science of Cave Diving will be at the BUEI tomorrow at 7.30pm. Tickets are $20 for members and $25 for non-members available by calling 294-0204 or visiting BUEI’s Oceans Gift Shop. For more information about Ms Heinerth and the world’s oceans, see www.wearewaterproject.com or www.intotheplanet.com