It's no easy feat being a modern day explorer, but 82 pioneers are on a mission to map the one place on Earth that remains a mystery.
These explorers are the Great Barrier Reef's Master Reef Guides, a collection of divers dedicated to sharing discoveries about one of the world's seven greatest wonders.
Together, the 11 divers based in the Whitsundays have amassed a whopping 41,791 scuba dives.
Despite being an iconic tourist attractions, Master Reef Guide Crystal Littlefish says travellers only experience about seven per cent of the Great Barrier Reef.
She said visitors taking a single boat trip would be the equivalent of exploring a single strand of hair on a human's head.
"It's the size of Victoria and Tasmania combined, it's 2,300 kilometres long," Ms Littlefish said.
"This place is enormous."
Opportunity to change lives
But Ms Littlefish says that for visitors and divers even that tiny exposure to the reef is "life-changing".
"I don't say that lightly," Ms Littlefish says.
"I've experienced life changing moments myself and once-in-a-lifetime encounters with marine life that you know in that moment they're never going to have any other encounter with another human."
"That's an extremely special, unique opportunity and moment to have and then be able to take people into the water into this world that they fear, essentially ... and give them an experience that changes their life."
While being able to share the reef's unexplored realms is a career highlight, Ms Littlefish says the work she and her colleagues do above the water is just as important.
Master Reef Guides are striving to be the leading reef guides and interpreters on the Great Barrier Reef.
Ms Littlefish says this often involves going into schools to educate the next generation about the reef and how best to protect it.
Reef health a message of hope
Fellow Master Reef Guide Johnny Gaskell is a marine biologist whose week can involve supervising management projects and taking coral surveys to simply exploring the reef.
In his latest outing he took his first passengers on a special tour as part of the Whitsunday Reef Festival.
"I've seen hundreds of sites that are in incredible condition, and then on the flip side, I've seen hundreds of sites that have been impacted as well," Mr Gaskell says.
He says crown of thorns starfish, cyclones and bleaching have all damaged the reef.
But wherever he has seen detrimental impacts, Mr Gaskell says there have been "little havens" that show promise of the area's restoration.
There is one obstacle Mr Gaskell fears most, however.
"It's really important that we still work hard to reduce carbon emissions," he said.
"At the moment we certainly haven't lost the Great Barrier Reef but we have seen what can happen if the conditions are in its favour."
