"A healthy ocean is an ocean with sharks. Take away an apex predator and it’s like removing the lions from the Serengeti. It won’t be long before the gazelle, zebras and wildebeest have multiplied and eaten all the grass. And when the land is laid bare the grazers will starve to death. Predators are crucial for a healthy ecosystem – be it on land or in the water."

“I don’t know of any sport where the goalposts can shift the way they do with endurance swimming.”

“If you have a passion, follow it. It's the best barometer of what you will be good at. And choose a career that you enjoy – the extra money of a job you detest isn’t worth it.”

“I always tell young swimmers: 'Practice things until you can't get them wrong. Not until you get them right.' There's a big difference.”

“No matter how tough my day has been, when I dive into the sea, the world seems perfect.”

“The trick is to make fear your friend. Fear forces you to prepare more rigorously and see potential problems more quickly.”

“I have been haunted by that swim through the whale graveyard and haven’t been able to get the image of the bones out of my head. Man hunted whales almost to the point of extinction, not seeming to care that we would lose one of the wonders of the sea world forever. It is the coldness of the water in Antarctica that preserves the bones and makes it look like they were left there yesterday but I like to think they are there as a reminder of man’s potential for folly.”