it is so hard to stick to
For me it looks like one of the simplest methods.
and there are so many things that could go wrong.
How big is that "so many"? I can think of exactly 3 reasons:
- you're rescued by others,
- you get out of the water somehow using your own efforts,
- you're kicked out of the water to land by waves or other kind of water stream (in an ocean, sea, or river).
The probability of all these conditions can be minimized with careful planning.
Even if you can't swim, at a certain point your body's reflexes will do anything in its power to keep itself alive.
What reflexes? The only reflex that may really delay drowning is the one that prevents aspiration of water, but it's quickly superseded by the breathing reflex, which forces you to inhale water, causing loss of useful oxygen and decrease in your buoyancy (due to increased average body density resulting from the replacement of air with water in the lungs). This latter reflex makes your death rather more probable than less likely.
In case if there is some panic (which doesn't belong to reflexes), it may decrease the odds of survival as well. The behavior of panicking people is often very far from acting in a way that would be optimal for surviving. In particular, many drowning subjects try to climb on their would-be rescuers, causing big troubles for those who are trying to help. Sometimes this leads to death of both the initial drowning victim and the would-be rescuer.
I feel like the only way it could be good is if you hurt your head to an extent that you can't think properly, like taking drugs or alcohol or making sure you hit a rock.
Effective sedation can be achieved by inhaling asphyxiant gases. It's a cheap, easy, and fast method.
Theres just so many other ways to go that are far more successful and peaceful, like hanging.
Why do you think that hanging is far more successful? The stats regarding lethality of suicide methods presented in the documents below indicate some advantage of hanging, but it doesn't look especially big.
The use of suicide methods largely determines the outcome of suicide acts. However, no existing meta-analysis has assessed the case fatality rates (CF…
www.sciencedirect.com
Firearms: 89.7%
Hanging/suffocation: 84.5%
Drowning: 80.4%
Lethality of suicide methods
Firearms: 90.3% (3027 / 3354)
Hanging/suffocation: 83.3% (9293 / 11148)
Drowning: 79.5% (527 / 663)
As for the level of comfort, drowning after gas asphyxiation could be better than hanging after gas asphyxiation, since hanging could cause a more intense brief discomfort during the period between the loss of bodily control and the loss of sensitivity. These methods should be close to each other in terms of comfort, and the choice mostly depends on the personal taste. Some people have aversion or fear towards drowning, some people dislike the idea of strangulation. I'd rather prefer drowning to strangulation of any kind.