He is out to break a world record, sure, but New Zealand freediver William Trubridge also wants to make an environmental statement.
Trubridge, who lives on Long Island in the Bahamas, will attempt to better one of his previous world records at freediving on December 3 - by swimming, unassisted by fins or weights, to a depth of 102 metres before returning to the surface.
This will be watched all over the world, the drama of the dive also creating a platform for his advocacy of environmental causes.
The holder of 15 freediving records is the subject of extensive media coverage, which he says enables him to speak up for the marine environment he holds dear.
CBS's 60 Minutes dedicated an entire episode to one of his attempts at a record freedive and there have been recent documentaries on National Geographic, CBC Canada and NHK, Japan's public broadcaster, among others. Numerous American newspapers have interviewed him, including the New York Times; the French media is taking a close interest in the December attempt.
Trubridge says life would be hectic, had he to deal with the burden of all this celebrity on a daily basis - but his routines of swimming, meditation, gardening and fishing go largely uninterrupted.
"Long Island is known as 'a family island', a real out of the way place, well off the tourist track. My wife Brittany and I myself live a relatively reclusive existence, without many uninvited visitors knocking on our door.
"After my nine years living here, the locals are well used to me. Some may still think I'm a little crazy, but professional fishermen, who know the environment, appreciate what I'm trying to do."
He is an ecological ambassador for New Zealand's rare and endangered Hector's and Maui's dolphins and promotes the Ocean Recovery Alliance, an organisation aiming to rid the oceans of plastic waste.
Trubridge says both issues can be solved: "These dolphins are among the few endemic mammals of New Zealand; they're found nowhere else. Numbers are so low we're told they could be extinct by 2030 if nothing is done but they could be saved quite easily.
"By contrast, protecting rare and endangered native birds can be an enormous task, with the need to get rid of predators in an area and so forth. But by the stroke of a pen, we could definitely save the Maui's dolphin."
Trubridge says legislation could fully protect the dolphins by eliminating gill netting and trawler fishing from their habitat. Genetic population studies - more has been done on these species than almost any others in the world - show that without pressure from gill netting and bi-catch, dolphin numbers would slowly make a comeback.
"Protecting them would mean that some people would have to find other jobs and, in the short term, some businesses might fold. But these are minor human concerns compared to loss of species, which would be irreversible. People can find new jobs, businesses can change but a species can't accommodate its own extinction."
Meanwhile, the problem of plastics polluting the world's oceans affects not one but many countries, he says. The answer is largely a question of education - especially in the poorer countries.
"People just do not know that plastic is not biodegradable. Even here in Bahamas, probably one of most educated places in the Caribbean, a high school teacher I met when I spoke at a high school last week, didn't know plastics took so long to break down.
"We're up against a huge level of ignorance. When people in those poorer countries, such as Haiti or Dominican Republic, throw trash out window of their car which gets into river and washed out to sea (or off their fishing boat), to them it's gone when they throw it away. They wouldn't really equate it with the stuff washing around out at sea."
Trubridge says plastics pollution in the world's oceans represents a challenge but could potentially be resolved within the space of a generation.
"We see when kids are apprised of how damaging plastics are and how long they last, they become a force for change. They go on to be involved as adults [who change things]. I feel that if the present generation were to learn about these plastics, especially in the poorer countries, we could pretty much eliminate plastics from the seas."
Trubridge is grateful to Steinlager Pure for underwriting his record attempt.
"It's a pure brand, compatible with what I believe in. Modest use of alcohol harms nobody in my view, and I'm looking forward to a couple of beers, hopefully to celebrate after we break the record. It's the only time I get to have a beer.
"Being associated with Steinlager is kind of full circle for me. I grew up watching its sponsorship of the All Blacks and Americas Cup. Let's hope the media coverage its helping to generate helps put the spotlight on these grave issues facing our environment."