Claims made about ascending vertical vs horizontal

[boulderjohn]

"...rendering your stops completely ineffective."

If vertical stops are "completely ineffective," does that mean that everyone who does stops vertically gets DCS? If those stops are completely ineffective, it must mean that doing such stops is the same as going directly to the surface without stopping.

Before I started tech training, exaggerated arguments like this turned me against a certain segment of the tech diving world. Years later, a key figure from the early days of that community was very active on ScubaBoard, and he constantly used that rhetorical strategy--arguing for a certain strategy or equipment by grossly exaggerating the benefits of one and grossly exaggerating the deficiencies of the other. If I gave you examples of his arguments now, you would think I was lying because of the absurdities.

So I wrote to him and suggested he abandon that strategy. I told him that when he said things that were so blatantly untrue, he was alienating a large segment of his target audience. His reply was illuminating. Those absurd exaggerations were indeed intentional, he said, and he would continue using them because over the many years he had been arguing that way, he had determined they were very effective.

EDIT: I believe his early example set the tone for others to follow in that path.

 

[wetb4igetinthewater]

The one that hit me just had two.

When Were You a Diving Stud?

Other than being hit by a fishing boat, screaming in for a fish weigh in during a no visibility summer storm in Delray, FL, I've had no outlier experiences. Can't leave it there dada, hit by a boat??????:popcorn:

scubaboard.com

I hope your tank took the brunt of it. A friend of mine was working on Oahu. He was run over by the boat he was connecting up to the mooring line. Fortunately the prop hit his tank. Would have killed him if it hit him in the back of the neck instead. I think you Florida folks, if you are going to ascend horizontally, you do so face up!

Are you sorry you weren't hit by a much nicer boat?

You owe me a new keyboard. I just finished cleaning up my coffee that you made me spit out.

So I see some disagreement that I attribute to the GUE camp, and a bit of overzealousness about trim. I did have a conversation about trim with a local GUE instructor, I'll just give his initials, enough for people who know him to identify him (K.L.). Now I hope I'm not misquoting him, but in no way does GUE as an agency expect people to be in horizontal trim. There are many reasons to break trim. Being in trim is preferred when finning so that you maintain depth while neutrally buoyant (as we all know, many people must keep finning while out of trim as they are negative).

For someone to claim that horizontal trim is better than vertical for offgassing, they'd have to provide some scientific data that had been peer reviewed by people like DDM, Dr. Mitchell, etc.. I am skeptical it makes a difference as how much does the pressure on the body change from the feet to the head when in a vertical position? The human body, to my uneducated guess, is pretty darn good about circulating blood.

 

[tursiops]

"...rendering your stops completely ineffective."

If vertical stops are "completely ineffective," does that mean that everyone who does stops vertically gets DCS? If those stops are completely ineffective, it must mean that doing such stops is the same as going directly to the surface without stopping.

Before I started tech training, exaggerated arguments like this turned me against a certain segment of the tech diving world. Years later, a key figure from the early days of that community was very active on ScubaBoard, and he constantly used that rhetorical strategy--arguing for a certain strategy or equipment by grossly exaggerating the benefits of one and grossly exaggerating the deficiencies of the other. If I gave you examples of his arguments now, you would think I was lying because of the absurdities.

So I wrote to him and suggested he abandon that strategy. I told him that when he said things that were so blatantly untrue, he was alienating a large segment of his target audience. His reply was illuminating. Those absurd exaggerations were indeed intentional, he said, and he would continue using them because over the many years he had been arguing that way, he had determined they were very effective.

EDIT: I believe his early example set the tone for others to follow in that path.

Bill Rennaker once told me a story about GI3. Seems they were diving together, GI3 had on doubles with his hands full of some other gear, and slipped on some steps and ended up face down in the water, at Bill's feet, head submerged. He was struggling a bit. Bill was watching. Someone else said, "Bill, aren't you going to help him" Bill responded, "Not yet."

 

[oya]

Horizontal ascent because it makes buoyancy and trim easier with a wide surface area presented to water resistence as you inhale and exhale, making movement in the water column minimal during the breathing cycle, so that one can retain absolute control for any event, from a team failure to simply floating, calmly, casually, and enjoying the scenery and everything in between:
Sensible

Horizontal ascent because you think the 1.5m ambient pressure delta will wildly affect offgassing differently in your feet and head:
Silly as hell

EDITED TO ADD: After reading a bunch of responses in defence of the vertical... yeah... sure... you can be vertical. But you're making life harder on yourself. Learn how to be horizontal instead of just saying, "I don't have to." Again... I don't care. Be vertical if you want. But it sucks.

Just a Trim

Had a great conversation yesterday with someone about, among other things, the absolute importance of holding still.Ask any diver at any level what they love about the sport and almost certainly some version of, "It's so calm and peaceful," will be early on the list of reasons. Floating...

www.xoc-ha.com

 

[johndiver999]

Horizontal ascent because it makes buoyancy and trim easier with a wide surface area presented to water resistence as you inhale and exhale, making movement in the water column minimal during the breathing cycle, so that one can retain absolute control for any event, from a team failure to simply floating, calmly, casually, and enjoying the scenery and everything in between:
Sensible

Horizontal ascent because you think the 1.5m ambient pressure delta will wildly affect offgassing differently in your feet and head:
Silly as hell

EDITED TO ADD: After reading a bunch of responses in defence of the vertical... yeah... sure... you can be vertical. But you're making life harder on yourself. Learn how to be horizontal instead of just saying, "I don't have to." Again... I don't care. Be vertical if you want. But it sucks.

Just a Trim

Had a great conversation yesterday with someone about, among other things, the absolute importance of holding still.Ask any diver at any level what they love about the sport and almost certainly some version of, "It's so calm and peaceful," will be early on the list of reasons. Floating...

www.xoc-ha.com

Obviously being horizontal presents significant surface area that will generate drag should movement occur. So it does provide stability and will allow you to respond when your buoyancy is not neutral.

On the other hand, ascending vertically provides much better situational awareness. For my type of diving, two divers can face each other and each can watch each others back for aggressive sharks coming in on your back. When you see their eyes bug out. It is time to spin and face the shark. It is much easier and faster to spin when vertical.

Also, if you have reasonable buoyancy control, you can remain in a vertical position and not rely on the “crutch” of being horizontal. Lol. It just isn’t a problem.

Hanging horizontally and looking up kills my neck.

 

[Darnold9999]

On the other hand, ascending vertically provides much better situational awareness. For my type of diving, two divers can face each other and each can watch each others back for aggressive sharks coming in on your back. When you see their eyes bug out. It is time to spin and face the shark. It is much easier and faster to spin when vertical.

..... or spin and press the shutter so the flash makes them veer off! This was with a wide angle lens - he was sneaking up on me. I spun and pressed the shutter - no time to aim. Too bad I didn't get a shot of my buddies eyes

 

[NW Dive Dawg]

I'll never get why being perfectly horizontal while straining to put the back of your head on your ass on ascent or descent is important to folks. Maybe they just think it looks cool. I dunno. The only real advantages I can think of are:

1) Descending in extremely low vis and wanting to avoid stirring up the bottom.
2) Less surface area to catch any current.

When descending or ascending vertically.........or while hovering vertically at a stop, you are just one simple flip of the tips from seeing everything around, above and below you in way less time than if you did that while remaining perfectly horizontal..

I'm in the dive and let dive camp. Anyone who has a my way or the highway attitude is a total PITA....

 

[boulderjohn]

I'll never get why being perfectly horizontal while straining to put the back of your head on your ass on ascent or descent is important to folks.

There is a known psychological phenomenon that I will simply describe as "if I'm working harder, I must be getting an advantage." A close relation to this in scuba is "if I am doing something really hard that you can't do, I must be a better diver. Now watch."

There is a kind of reverse effect to this. If you can do that harder skill but you know there is no good reason to do it, you nevertheless need to do it for fear that others watching you will think that you can't.

 

[rmssetc]

What is the most critical parameter of an ascent? Is it not the ascent speed and timing?

I think there is no single answer to your questions -- they are very dependent on the conditions.

For example, from Nm to 5m, I'd say that ascent speed and timing are the most important considerations (though "critical" may be too strong a word), but you should be able to control that regardless of your body position. In fact, getting vertical (head up or down!) may help vent air bubbles from your BCD, allowing more control of your ascent than remaining horizontal.

Staying horizontal will help in manuvering if there is current, obstructions (ie., reefs, kelp, etc), and to keep visual contact with your buddy.

Another consideration is how the ascent affects your ears -- it may be easier to equalize, avoiding a reverse block, when in certain body positions.

From 5m-0m the most critical parameter of the ascent is often avoiding surfacing into a boat propeller -- best done vertically!

a horizontal position on ascent requires neutral buoyancy, which again means you are more stable and if you stop moving you will lay still - making it easier to deal with a problem that takes your focus without losing control of the depth.

Huh? If you're neutrally buoyant then you will stop moving when still, regardless of your attitude (body position) in the water column.

 

[boulderjohn]

Staying horizontal will help in manuvering if there is current, obstructions (ie., reefs, kelp, etc), and to keep visual contact with your buddy.

In my early tech training, staying in that back-arching, head back horizontal trim was absolutely mandatory. Then I switched agencies and continued with my trimix certification in open ocean boat dives in Florida. I immediately noticed that I was the only one doing this. Everyone else was nearly horizontal, but not quite. As my new instructor pointed out, they were all having a much easier time keeping visual contact than I was. All it took was a comfortable turn of the head to see pretty much everyone in the group, whereas I had to turn my body to see people not in my immediate path. As we drifted in the current, I had to keep making those turns.