Ten-year-old Caleb Lewis sat with his sister on a jetty watching his dad sink below the water, unsure if he would ever come back.
It was the mid-1990s on a family trip from Melbourne to Adelaide which had come to a temporary halt near Mount Gambier.
"Dad told us all about this place called Piccaninnie Ponds, where quite a few fatalities have occurred," Lewis vividly recalled.
"It's an exquisite ecosystem, but one that if you are inexperienced it can very quickly become dangerous.
"Dad told us about that as kids, then put his diving tanks on and we just sat on the jetty waiting for him to come back — just waiting — going: 'What happens if he doesn't come back? What happens if the bubbles stop?'"
Fast forward several decades and Lewis, now 44 and a writer, has continued that tradition after unveiling his latest play, Cathedral.
It was a work State Theatre Company South Australia commissioned; originally to be about tuna fishermen and Port Lincoln, before a rethink saw it being based on the south-eastern city of Mount Gambier.
The production tells the story of a diver who is suffering from nitrogen narcosis (a change in consciousness and neuromuscular function) while at the bottom of a flooded sinkhole, how he ended up down there and how he will get out, if at all.
Dangers inherent with diving
As he worked on the production, Lewis got in contact with Mount Gambier diver Josh Richards, before spending time with him on the Limestone Coast.
Richards had his own story to tell which became part of Cathedral.
"There's a point in the play where someone escapes and there's a physical injury that's sustained during that escape," he said.
"That's drawn from a story I was involved in where I injured myself quite badly trying to squeeze out of a cave.
"Coming back out, I left one piece of equipment on, which was the one piece of equipment that stuck.
"I was halfway through this tight little hole and I couldn't go any further up or down and I wound up stuck there for six or seven minutes, which was pretty unpleasant," he remembered.
It was these stories that added to Lewis's many experiences with the water.
They included his dad being a diver who helped fish bodies out of the Yarra River, after people jumped off the West Gate Bridge in Melbourne.
The now Queensland-based Lewis studied acting and playwriting at Flinders University.
When he was 22, he visited his father who was working on an oil rig near Dubai.
Lewis temporarily became a firefighting instructor, which included time undertaking training for search and rescue operations, and underwater helicopter escapes.
That long history with water and survival stretched back to Lewis's grandfather, who was a bomber in World War II in Europe.
His plane crashed into the Danube River and he was one of two crew who managed to swim out of the rapidly sinking plane, joining the "goldfish club" for airmen who survived crashes.
It seemed fitting that water became that central theme when the State Theatre Company enlisted him to write Cathedral.
But writing it became deeply personal at a time in 2020 when the COVID-19 pandemic was at its worst and personal tragedies had hit Lewis.
"We suffered several deaths in my own family, in particular as a young boy, and I think part of the play was processing the grief — it's about a guy who wakes up in a dark hole and had to find his way out of it," he said.
"It's absolutely [got] autobiographical elements — I've suffered depression for years and I remember this incredible sense of release and relief when I was formerly diagnosed."
Walking to cope with depression
A critical factor in Lewis staying healthy is going on long-distance walks.
"That's made a profound difference, actually, and something I stumbled on," he said.
"There's a loosening up of the body and mind that came from ambling, of going for those long distance walks and you surrender yourself to the moment — you let go of all the anxiety."
Those walks included hiking Germany's Black Forest, fittingly where the Brothers Grimm gathered inspiration for their folktales.
"That was cool, that was a really terrific time," Lewis said.
"I brought a copy of the Brothers Grimm and I'd just pull up under a tree and read a couple of fairytales and wonder what might come walking down the path.
"I sprinkled plenty of breadcrumbs behind me so I didn't get lost on my way back," he laughed.
That ongoing battle with depression has changed his hardline stance on avoiding "escapist theatre", allowing his dark-themed plays to end with some optimism.
"There's got to be hope — you have to be able to lead them out into the dawn — I think 20-year-old Caleb would have written Cathedral with a dark ending," he explained.
Cathedral is playing at Adelaide's Space Theatre until May 21, with a tour of regional South Australia to follow.
