28 replies to this topic

[Dive_Girl]

One of the things I try to hold to hold onto as avid diver and dive instructor is remembering what thing were like when I was new. I never want those memories to become hard to recall otherwise I would lose a certain perspective I attempt to hold while teaching.

Reading another post reminded me of the first time I had to do a "free ascent." I remember the captain telling us he'd be running a live boat (also a new one for me) so we'd be doing free descents and ascents. Holy crud! I was nervous and yet I said nothing. I was too prideful.

So although I had been diving recreationally for about 6 years at that point, I was newly returning to cold water diving in the Puget Sound, after a warmer water location hiatus. I was also in mostly rental gear - I particularly remember the neon green fins. So as we approached our safety stop, I attempted to slow my ascent to stop in mid-water at 15' like my dive buddies. But I was so over-tasked trying to look at my buddies, my depth gauge, wriggling into the proper dive position, and trying not to breathe fast - I couldn't stop!! I just kept going and made two very typical inexperienced diver mistakes:

1. Instead of quick dumping air from my BC as my ascent was increasing, I turned into a head down position and attempted to kick back to my buddies; and
2. I wasn't fully exhaling.

I shot to the surface in an inverted position and to make matters worse, I think I must have kept kicking "down" for a solid 60 seconds before I realized my fins were actually out of the water, my neon green fins, mind you. At least the crew had no difficulty in spotting me....

Note, both of the mistakes I made are common and both can prevent a diver from stopping or slowing a descent because in a head down position, unless you have a quick dump at the back of your BC and know where to locate it quickly, you will not be able to dump air. Try doing that with 5mil gloves on too. Not fully exhaling just makes you more buoyant adding to the issue. After that I practiced free ascents on every dive even if I had a line. I now actively practice them with students too, hoping they can avoid an experience similar to mine.

How many of you are handy doing free ascents? DO you have tips and tricks to share? How many of you haven't made a free descent and have questions that could maybe be discussed and answered here?

[ScubaDadMiami]

What a timely topic! This is indeed my primary concern regarding my newly acquired habit.

Until I am able to do consistently proper free ascents on my CCR, I am not going to start doing the deeper dives that I was doing on open circuit. Not only do I have to manage gas expansion in the wing but also in the drysuit and counterlungs. At first, I felt like I needed an extra arm or two in order to keep everything under control!

After lots of practice, I had pretty good success at keeping the proper ascent rate and holding my stops on my most recent outing. Before then, sometimes I felt like I was bordering on losing control at any second. It is quite a challenge!

Your story reminds me of my friend that just switched over to diving dry a short while ago. Sure enough, on her first dive, she shot to the surface upside down, fins out of the water.

Edited by ScubaDadMiami, 11 April 2006 - 02:04 PM.

[intotheblue]

I usually do "bcd/buoyancy assisted" ascents. I make sure I am neutral at the start of my ascent and kick just enough to get started up. Then I carefully watch my tiniest bubbles (recreational diving) or ascent rate indicator and discharge enough air from my bcd/drysuit to make sure I never exceed their rate of ascent. It is important to make sure you arrest your ascent rate before you reach your stop depth, so you don't blow past it with your exposure protection also expanding and becoming more buoyant faster than you are compensating for it. I've seen lots of newbies not understand the first time they have on neoprene that they will become buoyant rapidly when they get that close to the surface, even though I have been careful to point it out... so I watch'em like a hawk until I know they "get it". While I am theoretically not kicking, I keep my fins/legs poised to perform an emergency "retro-thrust" maneuver to also slow the ascent by starting with legs togeher, flexing my fin tips outward, and performing a "split" maneuver to reverse thrust and slow down.

For tech dives, typically I come up an ascent line watching my timer/depth guage to keep my ascent rate very slow and to perform stops usually every 10 feet as planned. Sometimes this is a reel with lift bag sent to the surface and I can reel it in slowly as I ascend. The point in either of these scenarios is to come up slowly under control, rarely having to kick, but always having the dump valve handy to slow down the ascent. In a pinch, you can also EXHALE completely and rapidly to reduce your buoyancy and quickly slow your ascent until you get it stabilized and then can add/subtract gas to your bcd as needed, and resume normal breathing.

Is that something like what you were looking for D-girl?

[gcbryan]

Interesting topic. I've done very few boat dives that had a down line, most were live boat with free ascent.

Regarding tips I would say doing a horizontal ascent is more stable, everything happens more slowly, and if you need to kick down slightly you are in the right position to do so.

Raise an arm slightly to vent and to maintain control, take a big breath to get you started again.

Edited by gcbryan, 20 April 2006 - 12:41 AM.

[intotheblue]

Interesting topic. I've done very few boat dives that had a down line, most were live boat with free ascent.

Regarding tips I would say doing a horizontal ascent is more stable, everything happens more slowly, and if you need to kick down slightly you are in the right position to do so.

Raise an air slightly to vent and to maintain control, take a big breath to get you started again.

In certain areas, I like to do that too, but one thing to consider is that while horizontal you are not watching for boat traffic on the surface, or other obstructions. Also, you may find some people inadvertently dip their inflator too low and trap air in the bcd making it difficult to slow the ascent in an emergency. In mid water, I recommend being able to look up and "reach up". Also, seeing the surface sometimes helps people gauge their need to slow to a needed stop and can encourage them that they are going to "make it". That is an important habit to develope in the event you have to perform an ESA/CESA. Also, looking up makes it easier for air to escape your airway. It does get harder to watch your bubbles/ascent rate indicator if you look up too sharply, so practice this technique until you know how much to raise your gaze... Also, coming up facing a buddy lets each of you observe the surface behind the other... protecting you from all directions. If solo for some reason, spin 360 degrees and look all around as you near the surface. Sail boats/boards are awfully quiet and can cause a nasty contusion on your head if you don't "WATCH-IT"!!!

[Latitude Adjustment]

Very timely as Fingrabber has another thread going on upcoming dive trips and the Galapagos are mentioned, all dives there are free assent which is one of the reasons another travel agency, UDT won't even book you unless you have atleast 100 ocean dives. Many of my dives from the Nai'a were also blue water free assents, it's definetly a skill you need on many liveaboards.

[ereediver]

Good topic ! On my last dive, we were returning to a line that desended from a bouy to about 25 feet. The dive from there was on a slope to about 60 feet. On the way back and ascending was all well and good to about the 20-25 foot mark. I thought I had all the air out of my BC, and was swimming so I was more or less horizontal. Well I began to rise and was releasing air"I thought" but could not stop my ascent. So it became a free ascent without being planned as such. Body postion it seemed prevented me from emptying my BC. The good thing I guess was I kept blowing out air from my lungs trying to sink. CESA with out the emergency. No bodily harm , but I lost out on some dive time. So being well versed in free ascents could help even if your not expecting to free ascent.

[VADiver]

In my opinion the proper position in the water column is horizontal, period. You have better control, awareness and the ability to respond to emergencies better.

If your doing a free ascent you need to stop...shoot a bag (SMB) and continue the ascent. I would argue you will be able to look out for boat traffic better than if you were verticle in the water colum.

As for shooting a bag it's a skill that everyone needs but few practice. I'm at fault here too, so everytime I dive a quarry I send a portion of the dive shooting bags and ascending. Also ascent/decent drills are great to practice too.

[mantarraya]

Guess it is just a matter of where you have done must of your diving, but I'd say at least 80 percent of my dives have also been free ascents and descents. Seems very natural to me. Th exception is if I am not wearing enough lead, in which case, I might have to kick down on that first dive. After that, the gear is wet and the bubbles are out of the wetsuit, so no problem in staying horizontal and doing the free descent.

[6Gill]

The main thing I see with new divers is not keeping ahead of the exponentially increacing bouancy.A drill we use is starting at 20 ft take 30 sec to move up 3ft hold for 30 sec then up 3ft.If you have a downloadable computer you can check your results.It is the 9ft,6ft,3ft that pose the most challange.Start by doing this with a visual refrence then when thats working do it using only your depth gauge/bottom timer in open water.

[Dive_Girl]

The main thing I see with new divers is not keeping ahead of the exponentially increacing bouancy.

That is such a good point!!!

[BubbleBoy]

Guess it is just a matter of where you have done must of your diving, but I'd say at least 80 percent of my dives have also been free ascents and descents.

Ditto, except for the "it seems natural part". I still struggle with shallow depth buoyancy because of the greater sensitivity of the controls at lower ambient pressures. A little shot of air/gas from your tank to your BC at 15 ft. contributes much more lift than it does at 60ft.

When doing free assents, I usually creep up on my stop or ceiling very slowly while venting my BC, and then first use my lungs to achieve the final balance. Once I get completely neutral and stable, I then tweak my BC gas until my average lung volume is comfortable. Taking slightly smaller breaths also helps to limit vetical drift due to natural changes in my lung volume.

Shooting a lift bag does seem like a good way to add additional visual control in the process, though I've never seen this done on the sport boat dives I've been on. I think it would be a good idea to alert the boat captain in advance, otherwise they might mistake it for an emergency signal.

BB

[PerroneFord]

Very good topic. The only time I've had a line to work with was on my certification dives. Every other ascent and descent I've ever done has been free. I wouldn't know what to do with a line to be honest.

I ascend and descend horizontal in the water. I've gotten used to rolling right and left to check above me. I also try to practice coming up 5ft at a time, venting, holding, and then rising again.

My instructor has a pool that is 10ft deep. So I practice ascents and descents there. Just drop slowly over 30 seconds and try to stop within 1 foot from the bottom, then swim off. On ascent, I am horizontal, timer in front of me on one arm, depth guage in the other. I check above, then ascend a couple of feet and hold. Ascend a couple of feet and hold. Etc.

Some say they have trouble with this in shallow water. Pool practice gets it done. My home pool is 6ft deep and I work on it there. If you can do it in water that shallow, open water is cake.

Shooting a bag to get a visual reference is also helpful. Mark off your line in 10ft increments... when you get ready to move up, just wind in 10ft and hold the stop again with the spool as the reference point.

When I started diving again last fall, I used to cork in the last 10-15 feet. It was my suit expanding. I finally learned to get negative at about 20ft and use breath control to handle the last few feet.

I believe GUE in their tech class uses an excercise called 7 minute descend/ascend. Where you set a stop watch for 7 minutes. You have to descend and immediately ascend, and it should take 7 minutes all told. Just a matter of buoyancy control.

[drbill]

A few years ago, I had an occasion to realize why I should always carry my pony bottle regardless of what my dive "plan" was. As a videographer, I rarely have a specific plan since my dives are determined by the subject matter I encounter on them. They control the depths and directions I go (within reason of course).

I had "planned" to dive to only 40' so I didn't strap my pony on. I encountered something that took me down to just over 70' and then IT happened. After exhaling I tried to take another breath off my reg and there was nothing coming out. I immediately and largely instinctively began a slow free ascent as soon as I sensed the problem. I checked my two octo's and neither gave air, my SPG read 0.

So I was faced with a free ascent from 70' without a breath of air in my lungs to start (because I had exhaled). I made it but it took discipline.

Now I always carry the pony (and have even increased its size).

I also descend vertically (head up) or horizontally and rarely head down. The reason? It was the debris tube in my tank valve that clogged and stopped the air flow to evern the first stage.

Occasionally I'll practice a free ascent just to make sure my lung capacity will allow it.


Hmmm... I see others are referring to an ascent without a line. Mine probably is more a CESA (but a "free ascent" as well). Yes, 85-90% of my ascents are free. However, they are easier than doing one in blue water since we often have kelp rising to the surface from depths of 50-80 ft or so.

Edited by drbill, 19 April 2006 - 09:50 PM.

[Latitude Adjustment]

Bill you are not alone, when I first saw "free assents" that's what I was thinking. Did one from 90' when my J-valve got bumped down on a wreck and checked it after that about every two minutes till I got an SPG. I did another one from about 70' when I ran out of air retrieving the anchor. As you come up with your head back watching the bubbles it's amazing how much air is coming out of your lungs.