Problem ascending

[southernblue]

Hello all, As a newly certified ow diver, i am still learning my gear and techniques when am in the water.

Last week my brother and i did a wreck dive to 18m with a group of about 10, It was the best dive i have had so far apart from the ascent, as i am a little heavy with lead, it seems like i need a heap of energy to make progress towards the surface, it's like i dont even rise at all, making me slightly inflate my bc to get the ascent started. I do vent my bc on the rise up, but just can't seem to refine my technique, and end up shooting past the safety stop zone at 5m:no.

We planned a scallop dive for Saturday just gone, and began our dive late afternoon in about 12m of water.

I ditched a couple of bars of lead at the surface and descended a little lighter than my last dive. After 20 or so minutes we made our ascent, and again it was messy and unpleasent.

Is there any techniques we can use to help us clean up our ascents, and refine them so they will be safe, not like we have now?

I have attatched the dive data from the wreck dive and the 2 Saturday dives, i may be descending too fast also?

Any help getting me sorted with this is greatly appreciated.

Thanks in advance.

 

[Blackwood]

My suspicion is that you are never getting neutral.

If you are neutral in the water at depth, any increase in lift will put you positive. Even if you have 200kg of lead on you, if you are neutral with an average breath, a full inhale will put you positive.

You should control your ascent with your lungs rather than by adding air to your BC. You have to vent both, but since you can dump air from your lungs much quicker than from your BC, I don't think inflating to ascend is the smart decision.

Maybe a little pool work would help you get your weighting dialed in a bit more.

 

[tstormdiver]

You might look into a buoyancy course. They usually teach everything from proper weighting to finding your neutral buoyncy point & how to use the lungs to make minor adjustments. You can learn this on your own, but the course can help you to do it faster & you may even learn a few new tricks to do it (I only took half the course & know I learned a lot). It'll save you some time & a lot of headache.

 

[TSandM]

I agree with Blackwood. You're probably diving a little negative all the time. This is very common in new divers, especially if you are weighted so you're feet-heavy. If your body is angled up at 45 degrees, then every time you kick, you are driving yourself upward. In order to stay where you are, you have to stay negative so you have an equal force driving you downward. As a consequence, when you try to rise, you have to fight that negative force PLUS generate some net force upward.

Something my mentor taught me early on was to pause occasionally as you're diving along and stop kicking. If you sink when you do that, you're not neutral. You can even fine-tune it -- if you stop kicking and inhale, you should rise, and if you exhale, you should fall a little. If one of those isn't working, you know what you need to do with the air in your BC.

If you are neutral when you begin your ascent, all you have to do is inhale and you'll begin to go up. Because of the expansion of the gas in your BC and your exposure protection, you'll continue up once you've started. The only way to stop that is to vent air from something --lungs, BC, or drysuit (if you're using one).

Jonnythan on this board gave me a wonderful tip when I was fighting with my ascents at the beginning. He told me to take a breath and start up, then exhale. If exhaling didn't stop my upward progress, then vent. Joe Talavera, in my Rec 2 class, put the same idea into slightly different words. He said you have a window of depth up and down from where you are at any given moment. Within that window, the expansion (or compression) of the buoyancy gas you're using can be compensated for with whatever lung volume you've got. Outside of that window, you have got to use your BC (or dry suit), because you can't affect enough change with breath alone.

Good buoyancy control on ascent takes some of us quite a while to master (and the class I took this weekend also showed that "master" is a relative term!) But getting trimmed out to a horizontal swimming posture and getting truly neutral is the beginning of a good, controlled ascent.

 

[spectrum]

In addition to what has been said make sure you have a good reference. If I'm doing a free water ascent I'll watch my depth display. Since you want to be rising at no more than 30 feet per minute (1 foot per 2 seconds) look for a nice 2 count at each foot. If you accelerate just a bit vent just a bit. Watching this way can avoid a lot of deception and prevent a runaway situation. Remember that any change in buoyancy will take a few seconds to modify your motion.

As mentioned though the key is to be neutral in the first place. Being underweighted can be equally problematic so don't get carried away with shedding weight.

Have you done the "bobbing plumb at eye level with an average breath while your feet are crossed when you have a near empty (500PSI) cylinder and an empty BC at the end of the dive test? A deep exhale should sink your mask. A deep inhale will take your mask out of the water. With significant neoprene very little depth will be needed to let you say under at the end of the dive. In a swimsuit or shorty an extra pound or 2 might be nice. You should always have enough weight to allow for a fully controlled ascent.

Pete

 

[Ice9]

I've had that problem before in the quarry. With no visual reference, ya just gotta "fly IFR" with your computer and watch the ascent rate. I got used to it after a few times. Of course, once you get shallow, the surface makes a good reference for me...

 

[h90]

When I started the instructors/DM always gave me much to much weight. I remember 8 kg and now I do the same with 4 kg. That makes just everything more difficult.
Than under water you should just go up and down a little bit while you breathing but keep on the average same level (without kicking the fins, moving your hands). When you breath with a nearly full lung you should go up, with a nearly empty lung you should go down without the help of the fins/hands.
I as just shorty in tropic clima, dive with nearly complete empty BCD. I could use 3.5 kg instead of 4, but that I get problems on the end when the tank gets lighter.

If you use a lot of weights, having the BCD half full, you have a pretty hard time as beginner.
My buoancy was always terrible and many DM/Instructor just don't care. I had once the luck to dive with an old german DM and his wife alone (no customer) and he made a special buoancy course for me (my AOW was useless). In just 30 min he brought me to the point that I can hang arround in every weired position without any force pushing me somewhere.
If you can do, dive somewhere with sandy bottom and deep say 7 meter (so you can try something at 5 meter, but can't fall deep) and try to adjust yourself (bring 2 or 3 weight belts, so you can add or remove one under water).

 

[rawls]

From looking at your dive profile it seems you are ascending then dumping alot of air once you get to your safety stop. Then your are dropping back down. So you now have to add more air to get neutral againg. Like Blackwood said, I don't think you are ever getting neutral. You are over compensating. Your ascent rate looks ok. Try to ascend and dump air in short bursts, not long ones. Try to regulate your breathing pattern. If you are negatively buoyant it will just make matters worse. So try to get back in the water and do a buoyancy check...floating eye level at the surface holding a normal breath. Ideally it should be with a half full tank, but this isn't always practical. Adjust your weighting as necessary. And remember...short bursts.

 

[budgy]

Making mistakes is part of the learning curve. New divers are often tense and hold to much air in their lungs and rarely relax enough to exhale normally. They carry or are given extra ballast weight to compensate for this. If you adjust your buoyancy when your over weighted, you compensate with a bigger air bubble, obviously when ascending, a bigger air bubble expands more and is always more difficult to control than a smaller one. Regarding ascents, if your diving from the shore, follow the slope, if your not, use a shot line, blue water ascents are difficult to control, most people need a visual reference. One of the problems I found when starting out, was excitment and tension. Formative swimming lessons encourage people to breath and move forcibly through the water. Without some relaxation guidance it often takes quite a few dives for a new diver to relax enough to achieve optimum ballast. I find after a session or two concentrating on relaxing and slow natural breathing in shallow water many new divers can take off 8-10 lb of ballast.

 

[Twiddles]

Is your BC/Wing filling with water? Maybee stupid question but I find if I am neutral, ascending has never required inflation of my bc simply going vertical and one kick and I can start dumping air. If water is entering your BC/Wing at depth maybee your losing bouyancy and that requires you to inflate? Just a thought.