OctopusLover
Contributor
This happened on a liveaboard I was just in.
On day 1 we are split on two groups by experience. I'm in the less experienced group (<100 dives). Everyone is on Nitrox except a person in the other group. I ask them whether they've considered taking a Nitrox course before, they say no as they just like the fish and aren't interested in "the tech diving side". I figure this must be annoying to the rest of them, but since they're not in my group I don't give it much thought.
On day 2, on a casual conversation, I ask them whether they find it annoying to always run out of NDL before everyone else, they say this is never a problem for them. I figure they must just like to stay shallow, indeed they seem extremely knowledgeable about fish and spend all their time after the dives identifying fish the rest of us saw in the books so I imagine they must just stay shallow on the reefs.
On day 3, the two groups find each other in the water, at 25 meters. The other group splashed first, and the profile of the dive was supposed to be the same for both groups, starting at 30 meters. I notice I'm on 10 minutes of NDL on my Peregrine computer set to GfHi of 85. Inexplicably, this diver who is on air is under me, and stays there for a few minutes.
Later at the surface, I ask them whether their computer wasn't complaining, they say no. Perplexed, I tell them whether I can look at their computer, which looks rather old. You see, back in the day I posted here about finding a cheap used computer that would match the conservatism setting of my Peregrine on 85 for my partner (settled on a Veo 2.0), so I'm quite familiar with which old computers are liberal/conservative. At this point I was imagining this must be one of these ancient DSAT computers whose legendary-gets-people-bent liberalism I surely had underestimated. To my surprise, it's a Mares Puck. RGBM algorithm, the most conservative, specially on repetitive diving like we're doing. How is this possible? Is the depth sensor faulty and under-reading? Is it set to gauge mode and literally not calculating NDL?
My mind is confused as hell as I go through the settings. Last dive, 32m. Depth is correct. Oxygen %, 32. Ok... WAIT WHAT? They don't understand the horror on my face. They're not Nitrox certified nor understand anything about what this setting is. You can imagine the rest of the conversation. They're laughing saying this surely means they're immune to DCS, I'm in awe.
Turns out they loaned the computer to a friend in 2019, and this friend was diving Nitrox and forgot to switch it back.
I set it back to air, they still don't seem too convinced that Nitrox would make that big of a difference. They say they've been fine for years so it can't be thst different. Surprise surprise, on the next dive they do as usual and go into deco. They took the Nitrox course after that.
I still chuckle at the idea that they paid for all this Nitrox that in their mind, just made everything be like before I ****** it up for them, when they got the Nitrox experience for free and with no effort lol
And this is the story of how someone dived 100+ dives on air but with their computer set to 32% Nitrox with no apparent consequence. Not only that, noone thought it strange that they could dive with Nitrox divers without needing to ascend prematurely, which I'm almost more shocked by. In their defense, they were never supposed to know anything about Nitrox, in a way it's hard to pinpoint whose fault this is, you could argue they're required to read the manual but we all know most people don't. It feels like this is a bit of a gap in our procedures. But what about the instructors and dive masters who for 6 years and 100+ dives didn't notice the elephant in the room?
On day 1 we are split on two groups by experience. I'm in the less experienced group (<100 dives). Everyone is on Nitrox except a person in the other group. I ask them whether they've considered taking a Nitrox course before, they say no as they just like the fish and aren't interested in "the tech diving side". I figure this must be annoying to the rest of them, but since they're not in my group I don't give it much thought.
On day 2, on a casual conversation, I ask them whether they find it annoying to always run out of NDL before everyone else, they say this is never a problem for them. I figure they must just like to stay shallow, indeed they seem extremely knowledgeable about fish and spend all their time after the dives identifying fish the rest of us saw in the books so I imagine they must just stay shallow on the reefs.
On day 3, the two groups find each other in the water, at 25 meters. The other group splashed first, and the profile of the dive was supposed to be the same for both groups, starting at 30 meters. I notice I'm on 10 minutes of NDL on my Peregrine computer set to GfHi of 85. Inexplicably, this diver who is on air is under me, and stays there for a few minutes.
Later at the surface, I ask them whether their computer wasn't complaining, they say no. Perplexed, I tell them whether I can look at their computer, which looks rather old. You see, back in the day I posted here about finding a cheap used computer that would match the conservatism setting of my Peregrine on 85 for my partner (settled on a Veo 2.0), so I'm quite familiar with which old computers are liberal/conservative. At this point I was imagining this must be one of these ancient DSAT computers whose legendary-gets-people-bent liberalism I surely had underestimated. To my surprise, it's a Mares Puck. RGBM algorithm, the most conservative, specially on repetitive diving like we're doing. How is this possible? Is the depth sensor faulty and under-reading? Is it set to gauge mode and literally not calculating NDL?
My mind is confused as hell as I go through the settings. Last dive, 32m. Depth is correct. Oxygen %, 32. Ok... WAIT WHAT? They don't understand the horror on my face. They're not Nitrox certified nor understand anything about what this setting is. You can imagine the rest of the conversation. They're laughing saying this surely means they're immune to DCS, I'm in awe.
Turns out they loaned the computer to a friend in 2019, and this friend was diving Nitrox and forgot to switch it back.
I set it back to air, they still don't seem too convinced that Nitrox would make that big of a difference. They say they've been fine for years so it can't be thst different. Surprise surprise, on the next dive they do as usual and go into deco. They took the Nitrox course after that.
I still chuckle at the idea that they paid for all this Nitrox that in their mind, just made everything be like before I ****** it up for them, when they got the Nitrox experience for free and with no effort lol
And this is the story of how someone dived 100+ dives on air but with their computer set to 32% Nitrox with no apparent consequence. Not only that, noone thought it strange that they could dive with Nitrox divers without needing to ascend prematurely, which I'm almost more shocked by. In their defense, they were never supposed to know anything about Nitrox, in a way it's hard to pinpoint whose fault this is, you could argue they're required to read the manual but we all know most people don't. It feels like this is a bit of a gap in our procedures. But what about the instructors and dive masters who for 6 years and 100+ dives didn't notice the elephant in the room?
