how to ascend/ descend

[Nemrod]

With the current 30 FPM rule I would favor a horizontal ascent. Ascending horizontal means you are essentially using positive buoyancy to rise, in other words you depend upon your BC to go up and likewise to go down in a horizontal position you must go negative and consequentially you are using your BC to descend.

Between absolutely vertical and horizontal there are 90 degrees. Divers were taught swimming ascents and descents during the time before there were BCs and even after the BC was common, somewhat later, were taught not to depend upon a BC for ascent. Mostly due to the possibility of a runaway ascent.

In dark water and limited viz where especially there might be something above you like a boat (traffic or anchored) one might consider going vertical.

In practice, watching all sorts of divers, for example, if you are going hand over hand down an anchor line into a ripping current to the Spiegal Grove you are not going to be horizontal. Having good horizontal trim is efficient and the hall mark indicator of a good diver. Maintaining good horizontal trim and neutral buoyancy (or close) prevents the diver from bicycling and hand swimming both the hall mark indicator of a poor/new diver.

I try to use the smallest possible BC (including no BC) and the least amount of weight (and equipment) possible. I would not describe my ascents and descents as being vertical or horizontal but I adjust through the entire range of movement possible, slightly negative on ascent and slightly positive during my initial ascent before going neutral (especially above 30 feet).

I swim down, swim around and then swim back up, but if I have a BC then I use it to assist as modern trained divers do and when without a BC I still set my buoyancy negative initially so that as air is exhausted from my tank I become increasingly positive but not so much that I cannot hold a stop, it is a learned skill now, it used to be taught. I do not use more air this way as one might assume I have the SAC of a dead person because I control my breathing and I have learned long ago the most important consideration and hall mark indicator of a good diver, stillness.

Let yourself be still.

N

 

[TatianaSilva]

right , so ... if i deflate BCD on surface , descend horizontally , exhale, maybe add air to BCD if needed , is that a correct way?
and to ascend , start swimming forward, slow and horizontally and last few feet do it vertically and inflate BCD at surface ? if theres any mistake or forgetting something please let me know

 

[String]

PADI recommend vertical descends for reasons of it's easier to equalise head up and if someone hasnt got the hang of a controlled descent yet they can slow it by kicking. The also recommend vertical ascents and safety stops which i find utterly ridiculous.

Personally i do horizontal ascents and descents. I've got a larger surface area so more drag making fine control far easier and i can hold position in a current far easier. The only times i might switch to a vertical descent is in very poor visibility and a strong current where i dont want to risk skewering myself on something metal OR if i need to get down exceedingly quickly (then its head down swim vertical anyway). I cant think of a single situation where i'd ever want to do a vertical ascent or safety stop.

---------- Post added July 13th, 2014 at 07:52 PM ----------

right , so ... if i deflate BCD on surface , descend horizontally , exhale, maybe add air to BCD if needed , is that a correct way?
and to ascend , start swimming forward, slow and horizontally and last few feet do it vertically and inflate BCD at surface ? if theres any mistake or forgetting something please let me know

i use the rear dump, stick my backside in the air, pull the dump and duck dive to start a descent then horizontal after a metre or so. You will need to add as you go down. Remember a descent should be near neutral. Ascending just fin up slightly and assuming you're neutral expansion will take care of the rest, you need to dump as you ascend.

Im a bit concerned with all these absolutely basic questions though - all of this is/should be taught on day 1 of confined water training long before you ever get near an open water dive site. We're talking first 20 mins of discover scuba briefing here.

 

[TatianaSilva]

oh no , its just me that in my first dives i was so concerned about everything and quite a lot of info that i didnt really ask many questions so as day pass and read about it , etc just want to make sure. All dives were great and I was good with BCD, weights, skills ... no problem , just diving is not something that you can do everyday ... this is not football or tennis ... so for someone like me who wants to be sure about evrything before doing it i find it hard to not " learn " between dives if my next one is gonna be in 3 months or so

 

[String]

OW manual page 15 - 27 or so has this with plenty of diagrams to explain pressure/volume/buoyancy if it helps.

 

[NAM001]

For years i did all my ascent and decent's virtical, NOt till a few years back did i start taking the buoyancy aspects more seriously and that led to me doing it horizontal. Many in the tech arena will say that horizontal is the way to do things. Many cite deco reasons of having the body all at the same depth. In the rec world yoou dont do deco but overcoming the buoyancy challenges, for me anyway, is rewarding in it self. One learns to apreciate that skill when you find yourself ascending with out a line.

---------- Post added July 13th, 2014 at 08:07 AM ----------

You have to evaluate each ascent. If you have boat traffic it would not, in my opinion, be prudent to be horizontal going up and facing down.

right , so ... if i deflate BCD on surface , descend horizontally , exhale, maybe add air to BCD if needed , is that a correct way?
and to ascend , start swimming forward, slow and horizontally and last few feet do it vertically and inflate BCD at surface ? if theres any mistake or forgetting something please let me know

 

[Zen1300]

I find it interesting that when new divers ask what are considered "basic questions", some of the more advanced divers are surprised. I have questioned many of the things I was taught in OW, particularly since it was a slam-dunk course over a weekend. And if you get the basics half-way decent, you're likely to get less instructor time since they are spending time with the elevator kings/queens and nervous wreck divers. OW doesn't make you a competent or knowledgeable diver. It gives you the basics to go forward and experience and learn. Things that made sense in the book were explained even better by those here with more experience - either phrased a different way or just in a manner that gives us that "ah hah!" moment of clarity we needed.

Also, there are a lot of things taught in PADI that are contradicted here by others - descent/ascent just one of them. In my OW we descended/ascended vertically along a line. There was no critique of our ascents or descents. The instructor went up/down with the rest, but I don't recall any personal guidance. Likely because he was holding on to the runaway - as he should be. Not a reflection on the instructor, but the nature of being in a class with so many different types of people.

I like the horizontal descent/ascent methods described and will practice those at my next trip to the lake.

 

[String]

In my OW we descended/ascended vertically along a line.

By course standards the last descent should be no line/without visual reference...

There was no critique of our ascents or descents. The instructor went up/down with the rest, but I don't recall any personal guidance. Likely because he was holding on to the runaway - as he should be. Not a reflection on the instructor, but the nature of being in a class with so many different types of people.

That as all too often comes down to poor instruction. Proper ascents and descents are supposed to be taught, briefed, debriefed. Pressure, volume and buoyancy is meant to be taught, discussed, examined and reinforced in practice. From your description it sounds like too many people in the class which again boils down to poor judgement of the instructor.

It's very common. Courses are taught quickly, rushed and the absolute basics the standards dictate SHOULD be known often aren't.

 

[divin'dog]

oh no , its just me that in my first dives i was so concerned about everything and quite a lot of info that i didnt really ask many questions so as day pass and read about it , etc just want to make sure. All dives were great and I was good with BCD, weights, skills ... no problem , just diving is not something that you can do everyday ... this is not football or tennis ... so for someone like me who wants to be sure about evrything before doing it i find it hard to not " learn " between dives if my next one is gonna be in 3 months or so

Good that you ask questions... Remember, on SB, if you ask what time it is, you will be told how to build a watch... what kind of watch to build, what kind of strap to use, where to wear the watch, what color the watch should be, when to read a watch, when to wear backup watches, how to read backup watches, etc... but it's all with good intentions.

Personally, I ascend and descend in a way that is most comfortable for the conditions and situation, which may dictate what you should do. Try to be skilled doing both horizontal and vertical. One thing I was taught, when I was first learning and trying to control my ascent, was to slowly ascend in a spiral. It is easier to hold and control your ascent by "swimming" up, esp if you need to ascend in one spot (under a boat) vs slowly ascending as if you are going into shore. It worked for me at the time. It helped me sort a few things out until I could do the "typical" ascent.

 

[TSandM]

The last descent is done without reference . . . but I don't remember anybody telling me anything about HOW to get it done. (In fact, I did my last descent hanging onto my instructor, since we had lost one another on descent on the prior dive, but that's another story.). I finished my OW class without ever figuring out how to do a descent without falling on my back! It does not surprise me that someone would come here and ask these questions -- If you watch the OW videos, they'll show and say things that you will almost immediately see contradicted on this board. I know it's confusing to students, because it was confusing to me.

Tatiana, drifting slowly downward in a horizontal position, adding a little air to the BC to keep yourself from going down too fast (I do it when I clear my ears) works great if you are not in a hurry to get to the bottom, and new divers shouldn't really be diving in places where that isn't true. To ascend, you can either swim forward and a little up until you become slightly buoyant, or you can fill your lungs and breathe shallowly for a few seconds with very full lungs, which will also start your ascent (DON'T hold your breath!). Then you drift upward in a horizontal position, venting any time exhaling doesn't stop your progress upward. Or, if you are very clever, you can hold your inflator hose at the height where it's almost but not quite venting, and then as the air in the BC expands, it will come out on its own (this takes practice to get right!).

Horizontal ascents and descents do pretty much require that you be balanced enough to be still in a horizontal position. This may require moving your weights around until you are stable. Take a look at the articles on trim on THIS site -- there's a ton of good information there.