• A diver takes photos of a coral reef underwater

Rob Stewart was an award-winning filmmaker and diver who died tragically in a diving accident at the age of 37. Many questions still remain about what happened on that day in 2017 and who, if anyone, is to blame. 

Through interviews and investigative reporting, The Third Dive attempts to uncover the mysterious and disturbing circumstances surrounding Rob Stewart's untimely death. Below is an excerpt:


A diving accident is not dissimilar to a car accident in one respect – if you’ve ever experienced one you’ll remember that everything seems to be both moving in slow motion and yet very quickly at the same time. It’s usually over in seconds, but in hindsight there seemed to be all the time in the world. I remember diving with a young inexperienced diver in Lake Ontario on the wreck of the Katie Eccles. We were at about 30 metres depth and the water was very cold, no more than around 2 or 3 degrees Celsius. We’d only been under a matter of minutes when suddenly the young man was pulling on my fins and giving me an out of air sign – slicing his hand across his throat to indicate he had no gas to breathe. I handed him my spare regulator and he spit it out and tried to bolt to the surface. I knew if he went up too fast, he’d blow out his lungs, so I held on to his BCD and tried to hand him the spare regulator again. He spit  it out again, kicked me off and bolted to the surface. I checked my computer afterwards and saw that this all took a matter of a few seconds, but at the time, when I think and wonder what I could have done differently, the whole scenario replays in slow motion, like I have a huge amount of time to think things over. In that case, after he disappeared to the surface, I slowly followed him up, fully expecting to see his body when I got there. Through some miracle, he was still alive. We got him on board and called the Coast Guard. After a short stay in the hospital he was okay.

I mention my dive incident because I think it’s important to remember that the events that happened during Rob Stewart’s accident all occurred in less than three minutes. According to his dive computer, that’s how long Stewart spent on the surface from the end of the third dive until he disappeared, three minutes. And it was a turbulent three minutes. There was a diver down on the deck needing emergency first aid. The deck hand and Claudia Sotis were attempting to get control of that situation. Sotis was not cooperating, according to Steele: “He started yelling the words ‘ten percent’ over and over again. Then he got aggressive. His arms were kind of flailing around.… He’s actually grabbing the skin of my hand to try to pull my hand away from him. I wasn’t having it. I was going to keep that mask on his face. So, yes, that’s what I was doing with Peter. Eventually he started to calm down and then come to where  I could have a conversation with him later.” Sotis said he has no idea what happened. “I’ve never had any type of a diving event on the water.… In all the years of all my diving, I’ve never had a decompression hit, I’ve never had an oxygen problem, I’ve never had any problem that you could – when you go down the list of normal ‘what can happen to a diver,’ I’ve never experienced any of those events, fortunately. Knock on wood.”

Meanwhile, Rob Stewart was still in the water, and Dave Wilkerson claimed that while Sotis was being tended to, he tried to get the boat back over towards Stewart. “So I was back there, you know, on the stern yelling for Rob to grab the line, grab the line and that’s when I knew something wasn’t right. When he wasn’t swimming for the line, which you should be. You know we’re not moving that fast. He literally had to swim 10 feet to grab the line.” During those three minutes there was a lot of frantic activity, easy to second-guess in hindsight, probably tricky and difficult to deal with at the time.

Interestingly, in the midst of this confusion, the only person not dealing with the emergency was Brock Cahill. Wilkerson claimed that while he was moving the boat towards Stewart, he asked Cahill to help. Wilkerson was asked, “Where was Brock Cahill at the time you told Brock not to take his eyes off of Rob?” He responded, “So there’s the engine hatch that’s on the center of Pisces. He was actually, I think, standing on the top of that.… I think that’s the last place I remember Brock being when I told him to, you know, not take his eyes off of Rob.” Wilkerson was asked again, “Where was he facing at the time that you told Brock Cahill not to take his eyes off Rob?” and responded, “He was facing off the stern where Rob was.” Wilkerson is asked a third time, “And at any time before Rob disappeared from sight or you were told by Brock that Rob disappeared from sight, had Brock ever alerted you to any situation that his friend was in distress?” Wilkerson responded, “Not at all.” The lawyer continued to probe. “So the first time Brock said anything about Rob that day after they came back up in the water was that Rob disappeared?” Wilkerson responded, “Where is Rob, and that’s about the very quick period that it took me to turn the boat.” Cahill denied that this interaction took place. When he was asked, “Do you recall Captain Wilkerson asking you to keep your eyes on Rob?” He replied, “No.”

Claudia Sotis said that she just assumed that Cahill and the captain would deal with Stewart. She and the mate were busy with her husband, “and Brock … was standing there.… He didn’t attend Peter at all.” Nonetheless, Cahill seemed to be the first one who spotted that Rob Stewart was no longer on the surface. During his deposition, he  was asked, “I know this is a tough question, but what was your reaction when you looked back to see where Rob was and he was no longer on the surface?” Cahill responded, “I basically screamed, ‘Where’s Rob?’ And it was one of panic.”

Wilkerson remembered, “I turned the boat there and literally the ten seconds for me the turn the boat around is when he vanished.” Steele said, “At some point when I was holding the mask to Peter, I heard somebody say – I don’t know who – but I heard someone in the background say, where is Rob? That’s the first time I heard something.” Sotis slowly recovered and said his first thought was, where’s Rob? “I came to, I became very aware, again, it was, it wasn’t like I was foggy after that, and  as soon as I came to, I was feeling quite fine, and that’s when I heard that they were looking for Rob, they couldn’t find Rob. And at first, it just seemed like well, that’s silly because Rob’s right there, you know, because they couldn’t see him or they turned the boat the wrong way.” Steele confirmed that Peter Sotis’ first concern was for Rob Stewart. When asked, “Did Peter Sotis have any conversations with you after he came to?” He responded, “Yes. The first thing he asked me was, ‘Where is Rob?’” Sotis said, “They were looking for him on the float ball, and so I assumed, at that point, that maybe Rob went down on the float ball, who knows, but the last thing that was on my mind was there could be anything wrong with Rob.”

Excerpt from The Third Dive: An Investigation into the Death of Rob Stewart, by Robert Osborne (RMB 2020)