It is six days on a 15-meter sailboat.

The winds die down only as they approach the continent.

They then arrive at Paradise Harbor.

"When our boat finally sails into calm waters I feel as if I am lifted from hell into heaven," says Lu. "It (Paradise Harbor) is such an appropriate name."

It is January, the summer has come to the Antarctic. The air temperature is between -15 C and -10 C and the water temperature is -2 C.

Lu dons a 9-millimeter-thick diving suit made of rubber. She normally wears a 3-mm-thick diving suit when she practices back in Hawaii.

When she dives into the cold water, her heartbeat becomes quicker out of anxiety and excitement - a bad sign for freedivers.

"You have to relax to reduce the speed of oxygen consumption, so you can stay down a bit longer," says Lu. "So when I ascend from the water, it is very energy-consuming and I have to keep encouraging myself to hang on."

She also feels her head aching due to poor blood circulation caused by the cold water.

"My face, fingers and toes ache, and after a while they just go numb," says Lu. "I feel that I am a freediving novice because my body moves awkwardly, and I need to practice every technique."

The surrounding icebergs, made of fresh water, release small bubbles as they dissolve gradually in seawater.

The experience is like diving into a champagne flute, beautiful yet dangerous since the icebergs may suddenly collapse because they are melting.

Meanwhile, Lu and the team shot a short documentary of them freediving, kitesurfing and snowboarding in the Antarctic and uploaded it on YouTube.

In February, she went to the Bahamas to shoot another video with underwater cinematographer Kay-burn Lim. This time, she was diving with tiger sharks.

In March, they flew to Sri Lanka, and shot a video with blue whales and sperm whales.

Through those videos, she wants to share the beauty of nature and raise people's awareness of ocean conservation.

"Once you have dived with those creatures, you won't want to hurt them," she says.

During a diving expo in Shanghai in May, Lu initiated a campaign "Save Ocean, One More Chinese Freediver" with her diving suit sponsor BestDive.

Later that month, Lu competed in an international freediving competition Deja Blue in Grand Cayman of the Caribbean, where she retained the female champion title.

Besides being a freediver, Lu is a pharmacogenetics consultant, giving advice to her clients on the use of medicine according to their genetic profile.

Speaking about her philosophy of life, she says: "It is like a journey. I want to try new things."

But ask her about the journey to the Antarctic and she says: "I'd love to go back again, just not on a boat."