(CNN) — Four letters — H-E-L-P — saved an Australian couple who spent 26 hours in a crocodile swamp. 

Shantelle Johnson and her partner, Colen Nulgit, were on a fishing trip in the Northern territory Monday when their vehicle got stuck in a bog. 

Despite their efforts, they were unable to get the car out, so they spent the night in the marsh. 

But the couple noticed crocodile tracks nearby, making it difficult to get much rest. After the tide rose, the two took their possessions — and their dog — and left their car. 

They spelled the word, ‘HELP,’ in the mud, and rescuers flying overhead saw and ushered them to safety.