Free diving is impossible to comprehend for most of us ...
As soon as you train and see what the body is capable of, it becomes more natural. We don't understand our potential.
Do you experience fear?
I get a fear of failure, which applies to any sport. But I don't feel afraid of going deep. It's a beautiful experience that I look forward to. As a kid I grew up on a boat and was in the water almost 24/7 so it was a natural place for me to play and have fun.
Tell us about your childhood ...
My family left England when I was 18 months old and sailed through the Caribbean and Pacific - we lived in the British Virgin Islands and Tahiti. We got to New Zealand when I was five and sold the boat when I was 10. So my first 10 years were on the sea.
What is the free diving attraction?
The peace. All sensations, even light, are muted. It allows you to go inside yourself more which is a very profound experience. I didn't hear about free diving until I was in my early 20s but was hooked when I gave it a go. There is a freedom to move in three dimensions. You shut down rational thinking because it consumes oxygen. The pressure causes a narcosis which slows the mind even more. You get in that woozy state.
What happens to the body?
The pressure compresses the lungs so you lose buoyancy which allows you to freefall but makes it harder to come back up. The body shuts down blood flow to the periphery when you hold your breath ... blood vessels constrict and that shunts the blood towards the core, the heart and brain. Essentially the body uses a set of reflexes shared between all mammals.
You named the 2010 record attempt Project Hector, which was not only a wordplay reference to breaking the 100m barrier ...
I wanted to increase awareness about New Zealand's Hector and Maui Dolphins ... there are only 55 Maui dolphins left. I use any exposure making world record attempts to help causes I support.
What are your other causes?
The main one is dealing with plastic pollution in oceans all over the world. The plastic is breaking down and getting into the food chain.
What influence did your father's success have on your life?
If there is a family attribute it is an adventurer attitude.My parents sold everything to buy a boat and sail across the ocean.
Your training techniques ...
I do a lot of yoga and breath exercises. In the pool I do a lot of laps with short recovery and also sea depth adaptation work. I like writing about techniques I use that can be applied to life. The most applicable one is visualisation.
If you weren't a free diver?
I chose a career as a geneticist but quickly opted out because I didn't enjoy being shut up in a laboratory.
Career highlight ...
My first world record and breaking the 100m barrier.
Lowlight ...
My first two world record attempts in 2005 failed - both ended in blackout, when the safety divers bring you to the surface.