Why dont I sink?

[Davidstealey3]

most new students do tend to hold a little air in the lungs when first trying to go down on the checkout dives. has to be just an involuntary reflex that they are unaware of, but it happens.

i also second the finning on the way down comment.

 

[BabyDuck]

i needed 40+ when i first started, and even then my instructor had to literally pull me down the first 15 feet. my first post-cert dive, i took off 20lbs. i think it was nerves & excitement & breathing off the top of my lungs instead of totally exhaling. now, in a single & wet, i need 10.

just to let you know, the phenomenon doesn't necessarily end just after ow. the same thing happened (with 12lbs instead of 20) when i first started diving dry. 4 dives in, the weight wasn't needed.

but i *float*. i can float with head, hands, & feet out of the water in a 'recliner' position with no effort whatsoever. i may die in water, but it won't be from drowning!

 

[Anderssub]

I had the same problems (i.e. needing about 26lb weight and still having problems sinking) when I first started, about two years ago. I had the same problem for my first 20-odd dives.

I'm not exactly light (6ft 2in, weighing 200 pounds). Theoretically, I know I'm carrying about 14 pounds of extra weight (above "ideal" b.m.i. for my height) but I'm quite muscular and this isn't enough to adversely affect my bouyancy. (I've seen hugely overweight divers using minimal weights).

After a lot of head-scratching from my instructor, we eventually discovered that I had air trapped in my (rented) BCD. I started using (and still use) the vent valves, instead of the feed/bleed buttons, which cured that problem. Over a period of time I have also modified my breathing (from shallow to deeper) so that I now expel more air when I breath out on descending - I think this also makes a difference.

Incidentally, as well as looking at how much weight you carry, you may need to look at the distribution. I now carry 8Kg (about 17 lb) of weights, but half of this is now around the top of my tank and half around my waist - and I feel very comfortable when submerged, because I'm more balanced.

Final advice - don't let this minor problem discourage you - you will sort it out eventually, and then go on to have many amazing experiences underwater.

Hope this helps.

p.s. This is my first post - I thought I'd save it comment on a problem I've been through.

 

[Teamcasa]

My guess is the holding my breath thing. ...I too will swear I wasnt kicking

To keep yourself from kicking without being aware of it, try crossing your ankles.

Final advice - don't let this minor problem discourage you - you will sort it out eventually, and then go on to have many amazing experiences underwater.

Ditto on all of the above but I'll add a few things. First, Relax. Good buoyancy control is one of the most difficult things new divers struggle with.

Keep in mind that the initial decent is not really important nor is it an accurate way of determining ballast. If you still have trouble, just dump all your air, flip over and kick down. After you reach 10-20 feet, all of the air spaces will be reduced and you will begin to descend without kicking.

Finally, do a proper weight check at 15-20 feet with only 500lbs or so in the tank.

 

[perdidochas]

I just finished my OWD. For some reason I seemed to need more than twice as much weight as anyone else? The instructor put 20 lbs on me in the pool, and was debating on adding another 5, and couldnt figgure out why I needed so much. Im only 5'11" and 185 lbs.

I was in a shorty 3 mm wetsuit and was using and Excursion BCD (we even tried a different BCD on day 2 incase there was some air trapped.)

I had no problem with the fin pivot (with the 20 lbs) or the neutral boancy float.

I am just curious as to why I seemed to need so much more weight than everyone else?

I think you're nervous and holding too much air. How do you do in a pool without a wetsuit?

 

[Lee Taylor]

Hello Solar,

I can relate to your concern. I use to have the same problem. My first remedy was to "swim down". If you flip over while on the surface and swim down about 3 feet, it works. Not sure exactly why it works, but it does.

My second remedy (to the horror of many a diver) was to add weight. I added weight until when I depressed the down button, I went down. This made me happy. As time passed, I noticed I was able to throw off some of the weight.

Sometimes BC's trap air. This is a fact. Some people are naturally very bouyant. This is a fact also.

You need to do what works for you personally. There are drawbacks to being overweighted. One the other hand, when I am wanting to lay on the bottom and dig and explore, I am very annoyed when I am not heavy enough and I slowly begin to rise off the bottom. In my case, I usually find this to be a case of air in the BC.

A while back, I had a very slow leak in my inflator mechanism that was constantly, slowly filling my BC with air, but that is a story I will save till another time.

It takes time to get things the way you are comfortable with. There will be some difficult dives, but there will also be some really good dives that make it all worth the effort.

Be Safe and Enjoy!

 

[paddler3d]

Most people do not take a full breath every breath. That would mean exhaling to completely empty and then inhaling to completely full, every time. The only people I have run into with that breathing pattern were a couple of Mount Everest climbers; I refused to certify them until they showed control of their breathing.

?????

They could climb to the top of the world, literally.

They functioned in a completely hypoxic state where your body is consuming itself and you wouldn't certify them until they could breath properly?

I just don't understand what you are saying about their breathing.

 

[AbyssalPlains]

Don't sweat it. Like the others said, divers who are brand-new to the sport often subconsciously do things that prevent them from sinking. With 20 Lbs in a shorty, you should sink faster than a rock (I'm 5'8, 150 Lbs, and in a shorty I only need a couple of pounds or so). But I'd say, just give yourself some time, get used to the whole new experience, and don't worry about the weight for now. With time you will find yourself shedding more weight. Also, on a side note, switching from a regular style BC to a back plate and wing setup allowed me to shed about half my usual weight right of the bat.

Don't worry, take it all in and just keep diving!

 

[MauiScubaSteve]

?????

They could climb to the top of the world, literally.

They functioned in a completely hypoxic state where your body is consuming itself and you wouldn't certify them until they could breath properly?

I just don't understand what you are saying about their breathing.

Breath properly for what? When I talked to them about their abysmal buoyancy and started talking about breathing for diving, the slightly older guy (40) started explaining how they were in training for Everest pretty much continually for the last few years. He would be going for his third time the next climbing season and the other guy would be going for his second. They had trained themselves to take complete inhalation/exhalations, at all times. It was actually quite annoying to talk with them, but pretty funny having drinks and appetizers at a bar. For all four OW dives they were oscilating from inflator to the sky near uncontrollable ascent to big arm flapping almost crash into bottom, in the very same rhythm that they talked, drank and ate. I had been telling them since briefing for OW Dive #3 that they had to learn how to control their buoyancy before I would sign them off, but they were exactly the same at the end of Dive #4. They paid $75 each for a 5th dive where they showed me adequate buoyancy control for 35 minutes.

 

[MauiScubaSteve]

Also, on a side note, switching from a regular style BC to a back plate and wing setup allowed me to shed about half my usual weight right of the bat.

You do realize this is totally wrong don't you? If for example the old BC was 2# positive and the wing was 1# positive then you would need 1# less weight to sink than in the BC. Same tank, same wet suit, same body, pretty much same weight to sink?