The ACT's "salty" population has just risen to one, thanks to the Canberra Reptile Zoo's acquisition of 10-year-old, 180cm long Charlie.

Canberra already has several freshwater crocodiles, but Charlie is the first saltwater specimen who will remain in the territory permanently.

Visitors to the zoo on Saturday and Sunday had the chance to get up close and personal with Charlie, who was allowed to roam outside his exhibit and amongst patrons with his snout banded shut.

Zoo co-owner and education officer Peter Childs said most visitors on Saturday morning were surprised by Charlie's calm demeanour.

"People have been surprised that such a prehistoric-looking creature is so easygoing," he said.

"Freshwater crocodiles are lot more highly strung – they're very wiry and afraid of everything – so they're much more likely to bite, whereas saltwater crocs tend to be a lot calmer."

Charlie is used to the attention, having spent most of his life performing in shows in Victoria.

Mr Childs said bringing a saltwater crocodile was his "holy grail", albeit one that will require renovations to the zoo once Charlie outgrows his first enclosure.

"There's just something so magnificent about them, not least of which is that you know when they look at you that they're sizing you up," he said.

"From here on in his growth will be incredibly slow, so we won't need to move him to his permanent home for another five years. We've already started work off-site on that enclosure."

The turtles and fish who currently occupy Charlie's enclosure do not need to worry about becoming lunch; they will be moved and the new occupant will be fed dead chickens and rats.

It's unlikely Charlie will be interacting with the public after this weekend, however; once he moves into the enclosure he will become territorial.

Mr Childs said he hoped Charlie's presence at the zoo would help educate visitors about saltwater crocodiles' importance to northern Australia's ecosystems.