Ascent/Descent Techniques

[Thalassamania]

I agree that there are "lots of reasons to do descents other than head down swimming descents." But all of those reasons are to solve problems that create abnormal circumstances ... if all is as it should be I'd suggest taking your cue from the animals that live in the ocean, head leads, tail follows.

 

[MRadke]

I find it easier to equalize while either inverted or in horizontal trim.

 

[Thalassamania]

I find it easier to equalize while either inverted or in horizontal trim.

A lot of people do. This is a problem that is, in most cases, easily solved by staying a shade ahead of the descent with your equalization. Maintaining a slight positive pressure in your middle ear solves a raft of problems.

 

[Akimbo]

I find it easier to equalize while either inverted or in horizontal trim.

A lot of people do. This is a problem that is, in most cases, easily solved by staying a shade ahead of the descent with your equalization. Maintaining a slight positive pressure in your middle ear solves a raft of problems.

Having your ears higher than your lungs makes clearing easier for everyone, by .445 PSI/Ft of sea water — but that shouldn’t make a meaningful difference to anyone with normal respiratory function. Thal’s point of slowing descent and staying ahead of equalization is far more important. You shouldn’t have to blow very hard at all, which has its own set of physiological ramifications.

 

[fjpatrum]

I have to say, as a newb, I'm trying to stay in horizontal trim both during ascent and descent but I can see good reasons not to do either, in the right situations.

I also dive a lot of neoprene occasionally and have to really kick to get down below 10 feet or so. After that, I'm usually fine.

 

[MRadke]

Having your ears higher than your lungs makes clearing easier for everyone, by .445 PSI/Ft of sea water — but that shouldn’t make a meaningful difference to anyone with normal respiratory function. Thal’s point of slowing descent and staying ahead of equalization is far more important. You shouldn’t have to blow very hard at all, which has its own set of physiological ramifications.

I actually have the best luck swallowing during descent. When I tried to hold my nose and blow gently into my sinuses, all I suceed in doing is moving mucus into my ears. Even sitting here at the computer, the only way I can consistently pressurize my ears is to hold my nose and swallow. I also think that the act of holding my head higher while inverted serves to keep the eustachian tubes open, at least in my case.

 

[scuba pro]

@ fjpatrum....

Keep in mind that the first ata is the most dangerous when getting down. That is where the greatest pressure change occurs. You need to remember that you have to constantly equalize in order not to rupture an ear drum. So be careful when kicking your face off to get to that 10 ft.(3meters) depth.

Desending in the horizontal position takes time and practice. By desending in the head up position allows for the air in the BCD to escape more effectively, since in the horizontal position you really need to get the LP inflator hose above your head for the air to escape out of the BCD. Remember that air wants to rise to the surface.

During the ascent, the same factor comes into play. While on the ascent, you want to ensure that the LP inflator hose is above your head in order for the air to escape, so that the air in the BCD doesn't expand in the BCD. By coming up in the head up position and looking up will allow you to see if there is anything on the surface that you may want to avoid; like jellyfish, other divers, and more importantly an oncoming boat that may not see you. By being in this haead up position, if you had to make an emergency descent to avoid getting hit by a boat, it would be more effectively to press the deflator button and descend allowing the air in the BCD to escape at a more rapid pace than in the horizontal position.

 

[fjpatrum]

@ fjpatrum....

Keep in mind that the first ata is the most dangerous when getting down. That is where the greatest pressure change occurs. You need to remember that you have to constantly equalize in order not to rupture an ear drum. So be careful when kicking your face off to get to that 10 ft.(3meters) depth.

Desending in the horizontal position takes time and practice. By desending in the head up position allows for the air in the BCD to escape more effectively, since in the horizontal position you really need to get the LP inflator hose above your head for the air to escape out of the BCD. Remember that air wants to rise to the surface.

During the ascent, the same factor comes into play. While on the ascent, you want to ensure that the LP inflator hose is above your head in order for the air to escape, so that the air in the BCD doesn't expand in the BCD. By coming up in the head up position and looking up will allow you to see if there is anything on the surface that you may want to avoid; like jellyfish, other divers, and more importantly an oncoming boat that may not see you. By being in this haead up position, if you had to make an emergency descent to avoid getting hit by a boat, it would be more effectively to press the deflator button and descend allowing the air in the BCD to escape at a more rapid pace than in the horizontal position.

Thanks for the reminder... I do have to equalize quite a bit the first 20ish feet and it takes me a little effort the first dive of the day. I've never had much issue down to about 10 feet, though, and after that I'm generally good to go.

As for getting air out of my BC, that's a non-issue since I either don't have air in there to begin with or I use the dump valve on my hip so in the horizontal position it's at the top already.

 

[danvolker]

Since pretty much all I do is drift diving, and often deep drift diving, I learned a long time ago the best way to go down is swimming at a fast speed, with no air in the wing/bc. Head stright down vertical descent, with air sucked out of the wing prior to hitting the water. I also dive in head first if I am not using my camera.
150 to 200 foot per minute descent rate, causes no exertion due to no air in wing, so you are falling negative, and kicking is like pedalling a bike down a hill

When a boat drops us on a wreck, if they have it marked, we can't miss it, given a fast descent...

The people who have been trained to float on the surface, then slowly begin to sink, then slowly do a horizontal descent may have an easy time descending with any buddy they have with them ( which is important..my way really limits who I can buddy with), but the slow horizontal descent can be a challenge if you want to get a good drop on a deep wreck, with a swift current.

Going up I go slow, and horizontal, of course.