Beware of False Prophets on Your Dive Trips

Diving instructors often think they know what they're doing. When you learned to dive, you probably put your complete faith in those who taught you. But later, perhaps you realized that being told such things as put extra lead on your belt "because you can always add air to your BC," or screw down the breathing resistance knob on your regulator "because you'll use less air" might not be the best advice.

Even later, with many dives under our belts, it's amazing how often and how easily some of us abdicate responsibility for our own safety to others because "they're the experts, so they'll know best." But do they? Even seasoned veterans, like our senior editor John Bantin, can get it wrong and trust the wrong people.

Do You Know the Way to Sorong?

Bantin remembers a particular dive trip with Tony Backhurst, owner of the British company Scuba Travel, when they were returning from Kri Island to Sorong on a boat driven by a local. "We assumed he knew the route," he says. "Assumption is the mother of all disasters.

"Having done this trip before, I remembered the route involved passing a chain of islands to our right. But we had started off in the poor visibility of a torrential downpour, and once the weather cleared, all we could see was open ocean.

"After three hours and low on fuel, the boat driver finally asked if either of us had a compass. Without knowing where we were, a compass heading wasn't particularly useful. Luckily, we were close enough to land for Tony to pick up a signal and chart their position on his iPhone. It was alarming to find we had totally missed the Bird's Head Peninsula and were heading out into the wide-open Pacific.

"Despite our protests, the boat driver would not believe it, and continued to head in what he believed to be the right direction. As luck would have it, we came across a fishing boat, and the occupants laughed when we asked which way to Sorong. Against what he thought was his better judgement, our boat driver reluctantly followed the fishing boat, and finally ran out of fuel when we entered Sorong Harbor. It had been a close call, and our local driver was proved to not know best."

A Smart Instructor or Just a Self-Serving Svengali?

As diving gets more complicated, with different breathing gases involved, we divers need to do more courses to fully understand what we're getting into. Again, most of us will put ourselves in the hands of someone who knows better. But they don't always.

As an example, let's use the case of an experienced young diver named Rob, who wanted to progress to ever-more-adventurous dives by using trimix with a closed-circuit rebreather. All the main dive training agencies offer courses on this, but still Rob had to rely on his instructor, Peter, who was certified by the International Association of Nitrox and Technical Divers, but whose interpretation of agency rules may not have been mainstream.

Even when you've completed the course, you may still tend to bow to the knowledge of the one who had taught you when you're out on a dive. Rob may have done this. When he analyzed his gas, he would have known the actual percentage of helium in it. If Peter told him to enter a different helium percentage into his unit's computer, to the one he'd actually be breathing, Rob may have done so, believing Peter had a convincing argument.

If Peter told Rob to alter the computer's gradient factors in order to remove the helium penalty (helium on-gases quicker but takes longer to off-gas than nitrogen), who was Rob to disagree with the expert?

If they did a dive together to 200 feet, and then Peter suggested they do a second that day, Rob would probably agree. After all, his guru was doing the same, so where was the danger? Perhaps it was Rob's idea, but if so, Peter didn't say no.

But as we know now, gurus can get it wrong. The "Rob" in this story is Rob Stewart, the Canadian filmmaker who made Sharkwater and died tragically in a diving accident in the Florida Keys in 2017. They were both probably suffering the onset of decompression sickness when they surfaced from the second dive, but when the anchor of their boat got caught, it might have seemed logical to plunge back to the seabed a third time, to retrieve it.

Stewart's family filed a lawsuit, claiming that his rebreather instructor and dive buddy, Peter Sotis, and the company that owned the dive boat were responsible for his death. (We've written a few articles about this, most recently in October 2018.)

Arguments still rage, and different theories abound. Some say it could not have been DCS because Sotis recovered later, after only brief therapeutic oxygen treatment. They say he suffered hypoxia, when the body is deprived of oxygen, but could that be a symptom of explosive DCS?

According to media reports, Sotis convinced Stewart to conduct a series of dives that were too deep for his skill level, and on the final dive, he came up too fast, paying the ultimate price. Stewart was not under instruction from Sotis at the time, but he might well have been influenced by the fact that Sotis had made many more complex and deeper dives than he had. What we do know is that the guru was recovered to the boat while the follower was left to his own devices -- drowning after having passed out in the water.

Remember, a lot of diving theory is just that. It often forms a set of beliefs that, under some circumstances, can prove to be untenable. Many diving instructors are driven by beliefs, with all sincerity, but they might not be right.

So don't put extra weight on your belt because you can always put air in your BC to compensate. There have been too many cases of new divers drowning because they put their faith in what their instructor told them. And, as stated above, even pros like Rob Stewart do the same. Divers should not be complicit in their own demise.

Don't rely on a solitary guru. Read as many books as you can on the subject. Listen to the opinion of more than one "expert," and ask questions of them if you're uncertain or confused about their instructions. Before or during a dive, it's imperative that any decision you make is an informed one. It's your safety at stake.

-- Ben Davison