Descending with grace

[Ian Wigg]

MikeFerrara once bubbled...
...Too many instructors lead students to believe that they should dump all their air. Not true... Bad move... don't do it.

Why? The reason I ask is that I was taught to get my weighting set up so that with all the air out of my bc at the surface I am just negative so that I decend nice and slowly. Gives me plenty of time to equalise, etc and makes for a nice controlled descent.

 

[nickjb]

I was taught to be neutrally buoyant at 3m with a near empty tank (and empty BC and snug drysuit). That means that on the surface with a full tank I am about 3kg negative. I'll agree with Mike here. Just dump enough air to start descending.

Once i start to descend I control my buoyancy so I am slightly negative and can drop slowly but stop at any moment if required. A lot of beginners (I did it) drop like a stone and sort themselves out when they hit the bottom.

In response to Dutchdown, If you don't fancy horizontal descents, have you tried tucking your heels up to your bum? Descending slowly will help

 

[MikeFerrara]

Ian Wigg once bubbled...


Why? The reason I ask is that I was taught to get my weighting set up so that with all the air out of my bc at the surface I am just negative so that I decend nice and slowly. Gives me plenty of time to equalise, etc and makes for a nice controlled descent.

Well, if your properly weighted you will be heavy at the start of the dive by an amount equal to the weight of the air you'll use. Right. 4-6 pounds maybe. What you describe will work fine with a near empty tank. It will work with a full tank too but you'll have a little air left in the bc. The point is to just get negative enough to begin the decent.

Aside from that lots of instructors have students wearing enough weight to sink a battle ship. When they dump their air they drop like a rock and leave craters in the bottom.

 

[tinman]

chiara once bubbled...
If you are going dry, ankle weights might be a solution.

I'm working towards my IE in mid-June, and as my feet always seem to refuse to stay down on fins' pivot and hovering, I wear them all the time while practicing skills in the pool.

... I was able to lose my ankle weights when I switched to Jetfins with spring straps from Aqualung fins. Perhaps a negatively bouyant fin might help you out and reduce the fatigue that ankle weights could induce when fighting a current, surface swimming or doing a diver tow...

 

[scubawife]

I had this problem my first 12 or so dives and would end up resorting to using the line to pull myself down. A DM helped me alot by telling me to just cross my ankles, point my toes and keep my legs straight (but not tense) and slighlty back, and look down. It worked for me. If I look straight ahead at all my legs start floating up. The other thing that also helped was dropping weight. Once I got down to the weight I needed to be neutral it made alot of difference for my descent. With too much wieght & a full tank, my upper body was just too out of balance and my legs, being lighter, would pop up. It's common for new divers to think they need more weight then they really do if they're having difficulty on the descent.

 

[Epinephelus]

Why, exactly, not dump it all? That should get you about 5 or 6 pounds negative with a full tank and headed down at a nice comfortable 120 fpm or so, just about right, thank you. So long as you can clear your ears ok, making a slow descent is just wasting precious gas & bottom time.
As for going down feet first, I know some folks find it easier to clear their ears in that position, and if you need to do it then that's fine. But personally I prefer to descend in about a 30 degree head down position. Fairly quickly.
E. itajara

 

[chiara]

Epinephelus once bubbled...
But personally I prefer to descend in about a 30 degree head down position. Fairly quickly.
E. itajara

Is that what the francophone diving community (especially CMAS and related friends) call "le canard" (the duck)?

I did so many during my 1* course I thought I was sick, then upon arrival at PADI they said it was no use.

I think I can still perform decently, but I would never use it again, feet first or horizontal is so much easier.

 

[jbd]

on the feet first descent. You have a negatively bouyant tank on your back. Many have their weights placed too far back on their hips and then when you descend you have the water "pushing" up on the bottom of your finswhich are in front of the centerline of your body. The result is that the dive is toppled over backward and descends out of control flailing his or her appendages wildly trying to regain control.

I teach horizontal descents with control.

 

[miesemer]

Epinephelus once bubbled...
Why, exactly, not dump it all? ...

When wearing a wetsuit, you'll need to add air to your bc as you descend to become neutrally bouyant, either as your descending or when you reach your desired depth. It seems to me, the air 'saved' by descending quickly with your empty bc is lost when you need to refill your empty bc at depth to become neutrally bouyant.

 

[Rick Murchison]

miesemer once bubbled...


When wearing a wetsuit, you'll need to add air to your bc as you descend to become neutrally bouyant, either as your descending or when you reach your desired depth. It seems to me, the air 'saved' by descending quickly with your empty bc is lost when you need to refill your empty bc at depth to become neutrally bouyant.

What?
The amount of air needed for neutral buoyancy at a given depth is precisely the same whether you start adding it early in the descent or during level off.
Rick