Heidi Knight (30) and Tony Pullman (42), of Branxton, New South Wales, came to New Zealand in April for an eight-day camper van holiday around the South Island.
But while visiting Milford Sound on April 29, Miss Knight went into labour, despite being only six months' pregnant.
''In Milford Sound - of all places,'' she said.
''My waters broke at 6 in the morning. I told Tony and we pretty much sat there for a few minutes thinking, `... what do we do?'.''
The couple contacted emergency services and a helicopter was sent to pick them up.
''While we were waiting, the Milford Sound emergency department came to sit with us, which were two old firemen.
''I think they were more nervous than we were.''
The helicopter took them to Southland Hospital in Invercargill, and about 15 minutes after landing, baby Riley was born.
''He was the size of my hand when he was born,'' Mr Pullman said.
Because Riley was three months premature, the trio were transferred to the neonatal intensive care unit at Dunedin Hospital where the Kiwi battler is still receiving treatment.
''He's been doing really well. We haven't had any dramas with him,'' Miss Knight said.
''The team here in Dunedin are exceptional.
''This is a special place. We haven't had to stress about anything.''
While Miss Knight praised the Dunedin community and the staff at NICU, she said she was starting to get the feeling staff were ''rubbing in'' the fact her son was legally a Kiwi.
''A lot of older ladies knit and donate things to the ward, and without fail, everyone else will get coloured things but we'll get black and white.''
So what happens in the future when the Wallabies play the All Blacks?
Mr Pullman, a Wallabies fan, said it may cause some unusual inner-family rivalry, but Miss Knight was comfortable with her son's future allegiances.
''You know what, he will definitely be a New Zealander. He'll back New Zealand because he can.''
As if the couple's holiday was not already eventful enough, they are now celebrating their engagement, after Mr Pullman got down on one knee last week.
''Thank God, she said yes.''
Mr Pullman will return home to work on June 22, and Miss Knight and Riley are expected to fly home on July 7.
The family hope to return to New Zealand when Riley is old enough to walk, and complete their South Island tour, Miss Knight said.
''We've got to go and see Milford Sound. We still haven't seen it properly yet.''
