This is a spoiler-free review of Jennifer Peedom’s Deeper, but it does reference real-life events that play pivotal roles in the documentary.

Most Australians likely know anaesthetist Richard Harris and technical diver Craig Challen for their roles in the 2018 Tham Luang cave rescue in Thailand. It resulted in both of them jointly winning the 2019 Australian of the Year. However, in Jennifer Peedom’s 2025 documentary, Deeper, their heroics in South-East Asia play only a supporting role. Instead, the documentary delves into the duo’s efforts to explore the depths of New Zealand’s Pearse Resurgence, one of the deepest underwater caves in the world.

On October 12, a screening of the documentary was hosted at Luna Cinemas in Leederville. It included a question-and-answer session with Harris and Challen themselves.

The documentary was like a profile feature in video form. It puts Richard Harris in the limelight and examines his psyche – more accurately, his love (if not obsession) for cave diving. Challen plays a main role in the documentary, as his close friend and right-hand man, who assists him in cave diving expeditions, but the film mostly explores the mind of Harris and his journey to explore what the Resurgence had to offer.

What this movie does well is how it handles its subject matter in a visual medium. Peedom mixes the cave diving jargon with emotional impact, visual flair and audio intensity. This was arguably the biggest challenge she had to face. She had to constantly thread the needle to prevent the audience from being confused about details, while not wrecking the immersion.

When the screening was over and the Q&A started, many among the crowd asked questions about Harris’s and Challen’s interest in diving. This showed that she had successfully stoked the audience’s interest so well that they were keen to learn more about something completely foreign to them.

That being said, there were some scenes where it felt like a massive information dump crammed into a small period of time. There should have been scenes where the documentary was allowed to breathe and let the scene itself do the talking without any exposition voiceovers.

The other elements that were overwhelming at times (but in a good way) were the cave diving scenes.

Their exploration of the Resurgence and their mission to make technological advancements in cave diving is where the ‘profile article in video form’ comes into play. As Harris dives into the depths of the water, we dive into the depths of his conscience. We are privy to his thoughts as he ventures further down, and as he does, the documentary tries to ace the sensory department. Moments of panic will put you on edge, and moments of stillness will have you awash with feelings of serenity … that border on anxiety.

The overlay of background music in these scenes was an interesting choice. I felt it dulled the sensory effect, and most (if not all) of the cave diving scenes should have had no music at all to hammer in the immersion and place the audience in the shoes (booties) of Harris. Sometimes, silence can be the best music.

The documentary also covers their role in the 2018 cave rescue operation in Thailand, the media attention they received for it, and their subsequent winning of Australians of the Year in 2019. This led to the question I asked during the Q&A.

I asked: “What was your immediate reaction when you found out you won the award?”

Challen’s response had an undoubtedly sardonic wit.

“I thought it was absolutely ridiculous. If we were the best Australia had to offer, this country’s got serious problems.”
– Craig Challen

However, it gave an insight into the duo, especially considering the documentary does explore Harris’ thoughts about the attention he received after the rescue mission.

The documentary asks a lot of questions and it proposes some profound answers.

I recommend giving this a watch.