A young couple who sparked an air and land search of isolated terrain in Australia's north say one of their biggest fears was attracting saltwater crocodiles.

Key points: The couple was found after being missing for 26 hours in a remote croc-infested area

The couple was found after being missing for 26 hours in a remote croc-infested area Police say they did the right thing by staying with their vehicle

Police say they did the right thing by staying with their vehicle Police also praised the couple for letting family know where they were going and what time they were due back

Shantelle Johnson and her partner Colen Nulgit lit spot fires and scratched "HELP" into the mud after their utility became bogged during a fishing trip to the Keep River National Park in the Northern Territory, close to the border with Western Australia.

The couple, from the East Kimberley town of Kununurra, and their puppy, Ace, were rescued by search teams at Barra Hole near Marralum on Monday afternoon after being missing for 26 hours.

Police say Colen Nulgit and Shantelle Johnson did the right thing by telling family where they were going. ( Supplied: Shantelle Johnson )

"We tried digging and we tried putting stuff under the tyres but it didn't budge," Ms Johnson said.

"We were pretty scared and worried, but we were just hoping someone would come."

Crocodile country

The couple's biggest concern was saltwater crocodiles, having seen tracks in the area where they were bogged. ( ABC: Iskhandar Razak )

The couple spent Sunday night in their bogged car but got little sleep.

They had earlier spotted crocodile tracks and were worried about the tide bringing the reptiles close to the bank.

"We were stuck on the marshland and we were right next to saltwater," Mr Nulgit said.

"Earlier that day we saw two, three croc tracks — they were about five, six metres long.

"We stayed in the car the first night and then we saw the water rising.

"We grabbed everything and took it about 20, 30 metres from the car."

The couple were also worried for their puppy, Ace, with crocodiles around. ( Supplied: Shantelle Johnson )

'It was overwhelming'

Luckily, the couple had told family where they were going and when to expect them back.

They had very little food but had a carton of water bottles packed.

By the time the search team spotted the smoke from their fire and the sign in the mud, the pair was getting worried.

"There were thoughts like that going through our heads but we had to think positive," Mr Nulgit said.

"I guess we were both upset but I had to put on my big boy boots and keep her calm and also try to keep myself calm.

"When they [the rescuers] came a bit lower to the ground, we jumped out of the car and started to wave them down.

"It was overwhelming, emotional yeah … we were pretty happy that we'd made it.

The couple's vehicle was spotted from the air after they lit spot fires and wrote "HELP" in the mud. ( Supplied: WA Police )

'It could have been a different story'

Kununurra police praised the couple for staying with their vehicle and letting family know where they were going.

"It could have been a different story if they hadn't done that," Acting Sergeant Dean Andrzejaczek said.

"It's always a good idea to tell family where you're going and what time you are expected back."

Mr Nulgit has pledged to invest in car recovery equipment for the next fishing trip.