At 77, Sylvia Earle, a distinguished oceanographer and aquanaut from the United States, still dives once a month into the deep sea to explore the mysterious blue world, of which less than 5 percent has been seen by humans.

This year alone, she has dived in more than 10 countries.

"Diving is addictive. You don't know what you will see in the ocean but you know it will be wonderful," says Earle, with eyes sparkling as she shows photos of colorful and exotic fish she has encountered during her 61-year-long diving career, to the audience of her public lecture in Guangzhou on Oct 14.

"As long as I can breathe, I will dive," she adds.

Also known as "Her Deepness", Earle has led more than 100 expeditions and logged nearly 7,000 hours underwater. She set a women's depth record of free diving to the depth of 381 meters in 1979. After that, she went deeper so that she could observe more species.

There are serious depth limitations to scuba diving, so Earle and her former husband, engineer Graham Hawkes, founded Deep Ocean Engineering Inc in 1982. They designed and built a submersible called Deep Rover, which took them to the depth of 1,000 meters in 1987.

In 1992, Earle left the company and founded Deep Ocean Exploration and Research to further advance marine engineering.

While film director James Cameron accomplished a trip in a submersible to the deepest part of the Mariana Trench, more than 10,000 meters below the ocean surface in March, Earle doesn't plan to break his record. "I never try to establish a record. The objective is to try the equipment to see if it is effective for scientists to explore the ocean," Earle explains.

"And I want to make everyone able to explore the ocean, not only a few scientists," says Earle, whose company is working on manufacturing submersibles that can be handled as easily as driving a car.

"People won't care if they don't know. The biggest problem we have in protecting the ocean now is people don't know how important the ocean is to them. They lack understanding, thus lack love for it," she says.

Earle is dedicated to educating the public on the importance of the ocean as an essential environmental habitat, through writing books and giving lectures worldwide.

In October, Earle visited four cities in China and made her first dive in Hainan province on Oct 19.

"I'm excited that I can finally know China from the inside out," says Earle. "The world looks to China. China is taking leadership in handling global climate change and I hope that China also takes the initiative to promote marine conservation."

With new technology, people can now dive to the deepest part of the ocean and even live underwater. In July, Earle led a team of aquanauts on a six-day expedition down to Aquarius Reef Base, an underwater ocean laboratory - a cylindrical steel chamber - in Florida, US.

"With the help of technology, people are able to explore more parts of the underwater world now. However, if we don't protect the ocean well, we will lose the opportunity to see the rest of this wonderful world," Earle says.

She reveals that many kinds of fish that existed during the days when she was a little girl have been eliminated by pollution. If people don't protect the ocean well, the remaining fish will face extinction soon.

xujingxi@chinadaily.com.cn