SHARK cage diving started out as a hobby for game fisherman Captain Rolf Czabayski. Founded in 1990, Calypso Star Charters was a side project for the Captain better known as the final world record holder for catching and releasing a 599kg Great White on a 15kg line before protections were implemented in the late 90s.
Now it's putting Port Lincoln, South Australia on the map.
The charter changed hands in 2006 to Rolf's first deckhand Andrew Wright, and Andrew's business partner Ron Forster. A year later they moved to introduce single day shark diving tours - something that had never been done before.
This week, Ron Forster was given the 'Outstanding Contribution by an Individual' honour at the South Australian Tourism Awards, largely in part for his work on shark diving. The business also took out silver medals in the Major Tourism Attraction and Adventure Tourism categories.
Natasha Becker, Calypso's marketing and office manager says that most of the business community warned the partners against the move.
"Contrary to what everybody believed and told him, Ron went ahead with it anyway. And that's completely revolutionised everything," Becker says.
A niche activity, originally taking anywhere from four to 21 days and costing thousands of dollars, opened the floodgates for budget conscious and time poor tourists.
"It has seen our business achieve tremendous growth from then on. It allows travellers to come in over the weekend and do it. Given the time bracket, it attracts people from worldwide now too, so they can do this as part of a tour around Australia. It really opened up the marketplace."
Their original boat, carrying 19 passengers, wouldn't cut it anymore. In 2009 the Calypso Star 2 was purchased and refitted. Today it has a capacity of 42.
The state government has also announced that the three operators of shark cage diving would, for the first time, be granted ten year licenses, allowing them to confidently invest in their business and attract more visitors to Port Lincoln.
It followed a review on the impact of cage diving, which has grown by 30 per cent in the past three years. Importantly, the government noted, the activity takes place in newly-created marine park sanctuary zones, boosting Port Lincoln's eco-tourism credentials.
Calypso have invested hundreds of thousands of dollars in upgrades based on customer feedback, including a massive gyroscopic stabiliser that just about eliminates the chance of seasickness, on-board wifi, and live-streaming underwater cameras for those who choose to remain on deck.
The business has since moved to refit the older Calypso Star to service the smaller sides of the business: Swim with the Sea Lions and Swim with the Tuna.
"We've got the ability to upsell it now. We introduced our Sea Lions in 2011. It was looking at the diversification of products and enticing people to stay in Port Lincon for longer, or giving them more of a reason to visit in the first place," Becker explains.
A shark cage dive might not be enough on its own, but shorter tours allowing customers the chance to swim with the local wildlife and industries cover the demographics they might otherwise miss.
Swim with the Sea Lions is a half-day tour from Port Lincoln and its seafood producers out to Hopkins Island, where visitors can swim up close with the sea lions.
Swim with the Tuna is a satisfying mix of industry and tourism - visitors are shipped out to a pontoon seated above a tuna pen, where they can swim amongst the tuna or see them through a glass bottom observation deck.
"Port Lincoln is so synonymous with the aquaculture industry and tuna exports, so this is a great opportunity for people to see it up close in the flesh - without watching it come off a truck during harvest.
Swimming inside a tuna pen.
"A lot of the people who come out and do the sharks and the tuna will say the tuna was scarier for them - this is a tuna half the size of you, coming straight for your face and you know there's nothing between you.
"But they don't contact you, don't worry!"
Those are the smaller products for Calypso - the bulk of their business is the shark cage diving. In fact, 80% of their customers said that shark cage diving was the sole reason they'd travelled to Port Lincoln.
"We're great for the region, what can I say?" Becker jokes.
"Economically, there's a large flow-on effect. The people coming in to do our tour are using the accommodation. They're going to the restaurants. They're using the shops, the taxis, the car hire."
The marketing effort behind the project is fairly severe, Becker explains. Port Lincoln is fairly far out of the way - six hours drive from Adelaide including a ferry trip, or a short regional flight across the Spencer Gulf - so it requires a concerted effort across all platforms.
Being one of only four places in the world where cage diving takes place, they have to take on their international competition by reputation alone. South Africa, Mexico and, more recently, New Zealand, are all vying for business.
"In a way we're competing with them, but speaking to our guests, there's quite a difference between the operations. We're very highly regulated, there's very strict safety standards.
"Our tour has the reputation of being very safe and in turn attracts people internationally to come here over some of those other operations.
"In South Africa they might have 30 operators going out, but some might have a little dinghy that can take out five people in a place where you've got sharks breaching."
"To us, customer satisfaction is the main thing, as well as promoting sustainability and conservation. It's about giving them the experience of seeing it but also educating them."
Calypso work closely with the CSIRO to conduct research on tagged sharks, revealing information about their behaviours and movements. They've also been a strong opponent of the Western Australian shark cull.
"The sharks are a majestic experience. It's quite mind numbing while you're down there. It's when you come out that you realise the extent of what you've just done."