A small group of free divers is throwing caution to the wind in the hunt for a prized catch amongst the deadly inhabitants of Darwin's waterways.

The waters are renowned for saltwater crocodiles, tiger sharks and box jellyfish, but the divers see the thrill in this adventurous style of fishing.

One of those divers is Rick Trippe.

"It's what I get out of bed for," he said.

"It's my passion and has been all my life."

The small group is taking an immeasurable risk to pursue their hobby. ( ABC News )

"You're a caveman. You're hunting your fish. Spearfishing is the most ecological and sustainable way to catch fish."

Free diving is the art of diving using only a single breath instead of breathing apparatus and is considered quite dangerous.

Mr Trippe free dives with friends by his side, including Seth Chin who is fine tuning his ability to dive deeper for longer.

"In the last six months I've taken it a bit more seriously," Mr Chin said.

"I've probably reached my maximum depth which is about 25 metres."

"In terms of bottom time you're looking at a minute or a minute-30 as an average dive".

Fishing in a 'lost world'

Their catches consist of some of the most sought after reef fish in the Northern Territory. ( ABC News )

According to Mr Chin, the waters off Dundee, 140 kilometres south-west of Darwin, are the best place for free diving and spearing because of their abundance of reefs and good visibility.

Dundee is also home to some the Territory's most prized table fish.

"You get anywhere from 15-18 kilo Mackerel which is huge," Mr Chin said.

"You get 5-10 kilo snapper, it's like you're spearfishing in the lost world."

The divers rarely come home empty handed, unless they choose to.

"I only pull the trigger when I'm going to eat it or a friend is going to eat it," Mr Trippe said.

"There's no by-catch, we don't leave things in the ocean."

Dangers at Dundee

Despite the fish bounty on offer, the divers face inherent risks in the water.

Apart from shallow water black outs, caused by a result of a low oxygen levels in the body, box jellyfish are also cause for concern.

"I use a wet suit mostly for the sun and also so I don't get stung by box jellies," Mr Trippe said.

"I do get stung around the lips occasionally by little things that float through the water."

Sharks are also prolific in the area; tiger sharks, bull sharks and reef sharks as big as 3 metres are never too far away.

"They sneak up behind you," Mr Chin said. "That's a bit scary"

"If I'm trying to pull a fish in and I feel something come behind me and I look and it's a three-and-half-metre nurse shark you're like 'oh what's going on there'."

Mr Trippe says lots of sharks are a sign of a healthy reef and ecosystem.

"They are beautiful creatures. "They have every right, they've got more right in the ocean than I have.

"When we see them they're just cruising around us."