SANCTUM – with TDI’s John Garvin

By Richard Taylor
“In Xanadu did Kubla Khan a stately pleasure-dome decree:
Where Alph, the sacred river, ran though caverns measureless to man…”
Samuel Taylor Coleridge, Kubla Khan 1816.
So starts SANCTUM the latest project of Executive Producer James Cameron (The Abyss, Aliens, Titanic, Avatar) and based on the real life story of underwater documentary maker and Producer Andrew Wight. Set to wet the appetite of every adventure seeking diver and to highlight extreme cave diving to audiences around the globe (the film opened globally on the 4th of February). SDI and TDI are pleased to have been associated with the production from day one. Not only is Script Writer and Actor, John Garvin, a TDI CCR Mixed Gas Instructor Trainer but he was also the Dive Coordinator. Add to this that a number of the main actors were certified SDI Open Water during the film and that 4 other SDI/TDI IT’s were also involved with the production and you can see why we are excited!

Many North America, European and even some Australian Members will remember John from his days in the Caribbean, surrounded by rum, barracudas and an eager clientele wanting top class Closed Circuit Rebreather Training! Having previously worked as an actor in the UK, with four years playing the lead in “The Buddy Holly Show”, John moved to the Turks and Caicos and opened ‘O2 Technical Diving’, specialising in CCR Inspiration training. With a 100% safety record over 8 years his diving CV is impressive; founding a team to map the incredible Caicos caves, working on several BBC and Discover Channel documentaries and providing logistics and dive safety support for UK Free Diving Champion Tanya Streeter’s world record breaking free dive to 160m/540ft in 2004. It was from here that John first met Andrew Wight and James Cameron and became involved in the Sanctum project.
 As inspirational to all CCR divers and Dive Instructors as his story is it is John’s involvement with Sanctum that is no doubt the highlight of an exceptional career.   As Dive Co-ordinator John’s list of responsibilities was itself demanding for one full time professional, let along his triple role as also Script Writer and Actor (John plays Jim Sergeant, the Surface Support Manager)[Ed. though forgive him his Australian accent!]. He had to firstly ensure that all actors and stunt divers were trained and qualified for the diving being done, attend daily briefings and assist Director Alister Grierson on how to visualize the underwater scenes, brief the actors and stunt divers, assign safety divers, ensure the rebreathers were prepped and monitor all underwater activities.
 It was also John’s experience as both a Cave Diver and a CCR Instructor that led to actual rebreathers being used on set [Ed. it seems SANCTUM is the first feature film to put real actors on CCRs inside an actual cave environment]. The shots are real with filming inside a huge enclosed tank at the Warner Brothers Studios on Australia’s Gold Coast (the same tank was used for the underwater scenes in Fools Gold) as well as in real caves and sinkholes in the Mt Gambier Region (the cave diving centre for much of Australia). In setting up the dive team John was the one who decided to use real CCR divers, including TDI CCR Instructors David Apperley and Barry Holland. 
As he explains: “Before underwater filming started it became very obvious to us that the (CCR) stunt divers who would be best suited to delivering the performances required were needed to be taken from Australia’s Cave Diving Elite. What we discovered was more important than their experience front of camera was their ability, through thousands of hours spent on CCRs in caves, to move like cave divers. 
“For example….where “Frank” [Ed. main character played by SDI Open Water Diver Richard Roxburgh] swims out through the body-choke tube, pivots effortlessly in the water, attaches a line and then swims off camera hovering just off the bottom David (Apperley) was able to do that in one take and was able to move his body in a way that absolutely communicates that this is a guy who has spent his life diving caves. It would be very difficult for someone new to closed circuit rebreathers to be able to make that happen.”
Even though the dive team were experienced with CCRs none had any previous dives on the unit used in the film. The VR Technology Sentinel CCRs were chosen for the need for a “big, tough expedition unit” explains John. Kevin Gurr (VR Technology owner and author of TDIs “Diving Rebreathers Manual”) had previously been involved with Cameron and the unit had the look the film designers and producers (and John) wanted! With as little clutter as possible the unit was easier for the actors to work with and the heads up display and back mounted display meant that it was easier for the safety and stunt crew as well. However, John is the first to admit that the actors had a spectacular learning curve, going from SDI Open Water Diver one day to CCR Try Diving the next! He was assisted in this by Brisbane SDI/TDI CCR IT Jason Blackwell also joining John on set as Sentinel Instructor and helping to prep and maintain the CCR dive kits.
It was here that John’s long time friend and SDI/TDI President Brian Carney stepped in with a specially designed TDI Sentinel CCR Course. This allowed the actors to complete their SDI Open Water course and then move directly to diving the CCR. In addition to learning the basic CCR skills they also had to learn how to use of reels, dive lights, helmets, full face masks and DPVs.  It was probably here, task loaded with his CCR off in front of him and attempting to negotiate a “no mount” squeeze that was purposely getting silted up that Richard Roxburg (aka “Frank”) found his “..worst experience ever” (though he could also be saying this about buddy breathing with a full face mask in the dark in 7m/23ft of water in an overhead environment!). As John points out, as much of the CCR diving as possible is done by the actual actors!
The decision to use rebreathers was one made at the very beginning of planning the film “ reflect actual cave diving”. However don’t expect an 100% authentic “no bubble” rendition of CCR cave exploration. Using the same technology used to lens Avatar, in fact two of the same cameras were used in the actual filming of SANCTUM, the movie explores the breathless journey through flooding passages, water filled caves and across plunging cliffs with the latest in 3D technology. With only a modest budget by Cameron levels (SANCTUM cost $30mil as opposed to Avatar’s $237 million) the producers wanted to show that 3D could be used in all movies, just to tell the story. “The idea behind using the 3D cameras is to make the viewer feel like they are actually swimming around these caves too" says the film’s Underwater Cinematographer, Simon Christidis.
John explains that “Bubbles look fantastic in 3D!”  So much so that aside from the five actual rebreathers used an additional two “open circuit mock ups” were made. Add to this face lit Full Face Masks and CCR/FFM Buddy Breathing and John is the first to admit that some of the more critical CCR Cave Community may find fault.
“But I think most divers are smarter that that” John says smiling. “They know that this is not a cave diving documentary and that there has to be a balance between expedition and high tech diving and the need of story telling… the need of the movie!”
Overall the underwater filming lasted just over four weeks, with three in the pool and one on location in South Australia. Going from the balmy 40°C/104°F studio pool, where all the actors needed was a 3mm wet suit, to the invigorating 15°C/59°F of the Mt Gambier caves and sinkholes provided its own challenges to the divers.   Not that being in a dive tank with 12 huge concrete cave sections, moveable pontoons, high powered electric lights, cameras, cables and 12 divers was any easier!
As the SANCTUM character Victoria says, ”Diving in caves…..what could go wrong?”.   Add rebreathers, actors who have never dived and a 7m deep 11million litre (23ft deep 3 million gallon) tank of water and, you can understand why John Garvin was the right man for the job. And all of us at SDI/TDI are happy to be along for the adventure and will be front of center with our 3D glasses when the film opens. See you at the movies!
(Note: look out the full Diving in SANCTUM and personal interviews with John Garvin in upcoming editions of the Underwater Journal).
Get the film info and see the SANCTUM Trailer at



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