Apparently drowning is subject to fashion just like everything else. According to a book I picked up recently, drowning was usually described as horrific and painful by survivors before the Romantic era, and as painless, even pleasant, by later generations.
During the hippie era it wasn't uncommon for survivors to claim immense tranquility as their lungs filled with water, and deep resentment against the rescuers who fished them out. You'd read comments like, "The only pain I felt was when air was rudely forced back into my lungs."
Since we have contradictory accounts, I feel free to come to my own conclusion, which is that it's horrifying. Drowning is oxygen deprivation, something hanged men re-act to by kicking wildly...surely a sign that they're not enjoying themselves.
Physical reaction to lots of things follow fashion. In the 50s few people were actually made sick by smoke in restaurants. A lot of sensitive types who fainted when smokers lit up 40 feet away in the 80s used to pay big bucks to get into smoke-filled clubs in the 50s. Remember the Beat cafe in "Toot, Whistle, Plunk and Boom?" Clubs like that were considered cool. Beatniks smoked like bandits.
I don't think the tolerance of the human lung changed, just people's perception of what their lungs can tolerate.
BTW, I'm not pushing smoking here. I don't smoke and never have.
A hundred years ago women were diagnosed as having hysteria much more frequently than now. Sure, social prejudice accounted for some of that, but it's also likely that women of that time really were more emotional in public about some things. They collapsed from bad news, wailed uncontrollably at the death of loved ones, got physically sick when certain things were discussed, and fainted more frequently. I don't think human physiology has changed since then, just people's perception of how their bodies are supposed to react to things.
You see this in the way some people react to fast food these days. When MacDonald's first put up franchises, long lines and positive comments were universal. Almost everybody in those days thought of MacDonald's as something you did for fun, like going to the Dairy Queen for ice cream. That changed during the hippie era when MacDonald's and Coke were recast as symbols of "The Man."
Once MacDonalds was perceived differently, people's stomachs magically changed too. The same burger they relished a short time before was now thought to be utterly impossible to digest. In the "Supersize" film above you can actually see the filmmaker throwing up from eating a big Mac and a large fries. Was he faking? Probably not.
It's funny because he looks so much like the kind of wholesome, Jimmy Olsen kind of guy who would have taken root at MacDonald's only one generation before.
Am I saying that fast food is equal in taste or digestibility to food that costs 4X more in a classier place? No, of course not. I'm just noting that human physiology has a way of serving up whatever kind of physical reaction our mind expects of it.
This is a bit off topic, but all that talk about drowning makes me want to share this video I stumbled on. It shows what the filmmaker saw in Drake's Passage, beneath South America. This isn't even a particularly rough sea, yet the threat of drowning is ever present. I recommend just the first minute and a half of the film.