Mad? Well, he is English by birth.
But no. When the world's best freediver, William Trubridge goes out in the midday sun, his ice-cool brain controls a finely tuned body. Whilst his sport may be viewed as "extreme", at its heart is incredible discipline, a relentless search for the body's physical limits.
And for pushing the boundaries, creating the circumstances for his own life, the former Hawke's Bay resident is to be cherished as much as any of his father, David's artistic creations.
Oscar Wilde once wrote: "Most people are other people. Their thoughts are someone else's opinions. Their lives a mimicry, their passions a quotation."
Not the 32-year-old Trubridge.
He left Hawke's Bay and found his place in the world, with much of his time now spent in the Bahamas where he recently organised, competed in and won the Suunto Vertical Blue, a freediving competition based around Dean's Blue Hole. It's described as "an awe-inspiring natural wonder" plunging to 203m just a few metres from shore.
Whilst background - early years travelling the world on his parents' yacht, learning to swim at 18 months old, and freediving to 15m by the age of 8 - has played its part, it wasn't until he was 22 that he discovered the competition which has become his passion.
There is no mimicry. Trubridge and his fellow explorers are going where no men have gone before. To depths on a single breath, further than the length of a rugby field, and back.
"It's four minutes that takes place in another dimension, where time is drawn out into an eternity - an eternity that lasts but a single breath," Trubridge explains.
It's the stuff of dreamers. Those who live to be different - who take us where our belief systems tell us we could not possibly go.
"The aim of life is self-development. To realise one's nature perfectly - that is what each of us is here for."
Wilde wrote it, Trubridge is living it.