They had failed to organise visas for that trip, becoming stuck in a trap of genuinely Kafkaesque perplexity as a result.

The so-called "Merauke Five" spent almost two months in rat-infested immigration detention, and were then sent to the local jail.

Their sentences in the local court of up to three years' jail, for violating Indonesian immigration law, were finally overturned in the Supreme Court. But it took weeks for the relevant paperwork stemming from that decision to be completed.

On arrival yesterday at Horn Island, the five finally went their separate ways, their enforced camaraderie set aside for now.

First on the agenda were beers and meat pies, followed by a night watching the State of Origin rugby league match - if they could stay awake that late.

"I feel like a goldfish that has escaped a pool of piranhas," Mr Scott-Bloxam said, shortly after touching down on Horn Island.

Mr Mortimer, said close friend Vicki Sparks, headed straight to his ocean-going yacht moored on nearby Thursday Island "to have a beer - and I wouldn't be surprised if he had quite a few. I can't say I blame him."

Mr Mortimer later praised the group's Indonesian lawyers but lamented the lack of translation services in Papua, which meant the five had little idea what was being said at their trial.

"It's hard to imagine that you end up in the highest court in the land for a misdemeanour case," he said. "We were all naive in thinking the system would look after us, and it never did.

"At the end of it, it was the Australian government, the Australian people and the Australian media that got us out."

Mr Mortimer said the group remained friends, despite their ordeal.

"I don't think there's any animosity at all. We're all mates. Whether we stay mates is another thing, but it'll be nice to have a break from them all."

Additional reporting: AAP