@mac64 The problem is that you say it is safer than trimix. Same with doing all on backgas. This seems to be impossible and unsafe for sure. Yes you can decide for yourself to dive on air to 60m. I don't mind. Maybe I will do the same if I absolutely need to do that particular dive and there is only air available, I have done enough dives on air and trimix to know what I can expect when doing it and can make a choice based on my personal experiences. But I cannot imagine to do such a dive
without decogas and I will never say that air is safer than trimix. It are the known facts and personal criteria that make the choice valid or not. But I also know divers that would never do it on air, simply because they already cannot do things anymore at only 42m. And this is repeating for them on every 42m air dive. So for them trimix is the only option deeper than 40-42m.
You can say that high helium trimixes are a waiste of the expensive rare helium, so use less please, but to state that air is safer, that is not true.
I don't think that any diver will ever say that air is the preferrable choice if the price for a trimix is only the price of a nitrox fill.
Are you a technical diver? Because you state you don't use any decogas?
And can you show a 25 minute bottomtime decoschema including gas consumption for your dive to 60m?
The argument you use air instead of several gases and no decogases means that seems like you don't know a lot of details about technical diving, or you ignore them. I am now really curious about your gasplan, consumption and decoschema for a 60m dive with 25 minutes bottomtime.