An age-old question: ways to 60m.

[old frogman]

Wait, you don't have one of these in your save a dive kit?
View attachment 909141
Amateur!

I have dived a real wet bell. That is not a wet bell. If you look carefully, it is a plastic dome attached to a some weighed down boards. It is static location on the bottom. Probably used for divers to enter in order to verbally communicate while on the bottom. If you look carefully at the divers, they are on OC scuba.

If that was a wet bell there would be wire cables leading to the surface to lower and raise it. There would
also be a communication cable. There would also be a control panel above the divers inside the bell cupola for controlling gas flow into the bell. The divers would probably be on surface supply with a full-face mask or helmet.

Please stop situating the argument and argue the situation. And please stop trying to pretend you are a professional. Clearly you are not.

 

[iliketopetsharks]

Bell, phone booth, upside-down bathtub, who cares. It's a professional operation with at least partial surface supply, not a weekend dive.

 

[iliketopetsharks]

People who did the dives were not trained in tech diving, they were amateur divers.
Todays average tec dive(r) would be way safer than what they did back then.

They decompressed on O2. Depending on your definition, wouldn't that be "tec"?

 

[CG43]

Wait, you don't have one of these in your save a dive kit?

I built a slightly smaller bell out of the transparent cover of an old dishwasher when I was 15 years old.
It was tied to a tree with ropes, and we could just about fit two heads inside to talk.

Many underwater tasks require special equipment, usually in addition to the standard scuba gear.
If you work underwater for some time and are very focused on the task, you can also occasionally forget that you are underwater. However, that doesn't make diving any safer.

 

[scubaozy]

20-30 Minutes of bottom time, in clear and relatively warm water and lots of people around you, great.
I dont say you'll have to die on air at those depths. But it is a fair-weather solution.

To be honest, it sounded like some folks argued as if people started dying, you thumbed each one of those posts. If you draw black and white conclusions from the increased risk of deep air diving, you are implicitly treating it like it is an existential risk.

Bell, phone booth, upside-down bathtub, who cares. It's a professional operation with at least partial surface supply, not a weekend dive.

How does that impact the physics and physiology? Wasn't that your argument? Because someone at the surface feeding you o2 will make your co2 go down or have no narcosis and do something dumb to kill your self?

They decompressed on O2. Depending on your definition, wouldn't that be "tec"?

We can debate about it, accelerated decompression might be considered tec but majority of them were diving single large tank with jacket style bcd, that is clearly no tec.

 

[iliketopetsharks]

How does that impact the physics and physiology? Wasn't that your argument? Because someone at the surface feeding you o2 will make your co2 go down or have no narcosis and do something dumb to kill your self?

If you have a surface supply of deco gas at a fixed depth you take out a lot of risks. Running out of gas, switching to the wrong gas, equipment failures etc.

We can debate about it, accelerated decompression might be considered tec but majority of them were diving single large tank with jacket style bcd, that is clearly no tec.

This shows that "tec" isn't clearly defined.
And tying the definition to equipment choice only is... debatable

 

[scubaozy]

If you have a surface supply of deco gas at a fixed depth you take out a lot of risks. Running out of gas, switching to the wrong gas, equipment failures etc.

Nobody stopping you to use single o2 tank to do accelerated decompression, in fact this is how majority step in to tec diving territory. Equipment failures apply to any diving as well as gas delivery problems. The reason o2 was supplied from surface is not the safety, it is the logistics, you can directly feed down from large tanks.

This shows that "tec" isn't clearly defined.
And tying the definition to equipment choice only is... debatable

Pointless debate. The point of that statement was that those divers were layman in comparison to todays qualified recreational tec divers.

 

[leadduck]

Has everyone read the entire article? George Bass is probably the biggest name in underwater archaeology and they had quite a setup if you continue doing some searches. Not exactly representative of what we are talking about here.

Who of you dive a wet bell to such depths for safety?

Oh, no one? Thought so.



I'm guessing none of you have actually worked on an underwater archaeological expedition. They are extremely safety conscious. One death would mean the end of a career, including the late great George Bass.

From a 2012 interview with George Bass in discovermagazine:

At Yassi Ada, one of our most skilled, experienced divers, Eric Ryan, was very near death when we pulled him from the water with an embolism. And then we had a sponge diver also brought to us with the bends, or decompression sickness, which is caused by nitrogen bubbles forming in your blood if you come up too quickly. It was horrible. He was calling out to his wife and Allah. He died during treatment in our decompression chamber.

Yes it was impressive what risks they took 50 years ago in underwater archeology in many ways. They often didn't know any better, don't blame them.
No, their safety record was not great. People died.

 

[CG43]

Given the choice between DAN, Duke University and the NEDU on one side and “old frogman”, “boarderguy” and a couple of other internet scientists in their ScubaBoard laboratory on the other side, I’m going to draw a deep breath for courage and take a wild leap of faith to go along with guidance from DAN, Duke University and the NEDU.

We are making progress.
From "flat earthers" to "internet scientists in their ScubaBoard laboratory" is quite a big step forward.
If we keep this up, we might end up exchanging factual and friendly arguments.

 

[ChuckP]

Yeah the Rouse's would like a word about deep air being "safe"

That isn't even a close comparison - a tragic accident but has way more merit about the physcology of diving.