Challenge of cold water diving

[seaducer]

Thanks for the tips so far!

I sometimes get the feeling that I am at the surface before being able to the all the right things, like dumping air. It feels like I can´t get the air out fast enough.
My BC is usually empty, I just use the dry suit for bouyancy. Should one use the BC also?

I do not dive a dry suit, but I understand you add enough air to the suit to be comfortable, and you use your BC for bouyancy.

If I am wrong someone will jump in...

 

[SteveAD]

I do not dive a dry suit, but I understand you add enough air to the suit to be comfortable, and you use your BC for bouyancy.

If I am wrong someone will jump in...

If you are weighted properly and wearing a non compressible suit, enough air to keep the squeeze off should be enough to stay neutral. If diving doubles it will probably be necessary to use the BC.

 

[String]

I do not dive a dry suit, but I understand you add enough air to the suit to be comfortable, and you use your BC for bouyancy.

If I am wrong someone will jump in...

<agency hat>Use the suit only so you are only controlling one form of expanding air on ascent</agency hat>

<personal>Enough air to remove squeeze then use the wing</personal>

IF your weighting is correct and its a single tank you can get away with using the suit. Any more than that though there's too much gas in the suit to be stable or comfortable.

 

[Teamcasa]

&#8230; It feels like I can´t get the air out fast enough. My BC is usually empty, I just use the dry suit for bouyancy. Should one use the BC also?

Two schools of thought. One school is use the suit for buoyancy and only use the BC for surface floatation.

Second is use Drysuit inflator only to remove the squeeze and use the BC for buoyancy control.

Both have merits and both are right with the major difference is what is your preference. If you use the suit, you have to be diligent about adding and dumping air as a drysuit can not dump air as fast as a BC. If you use the BC then you also have to remember to dump both to prevent an uncontrolled assent.

For me, (this coming from a new drysuit convert) I like using the BC for most buoyancy control and only enough air in the suit to control squeeze. On assents, I like knowing the suit is empty because I can feel the squeeze. This allows me to concentrate on air control in only the BC.

 

[Papa_Bear]

You have added more equipment in exposer suits, wet or dry, and have cut down on mobility! Every task becomes more of a challenge and air consumption goes up! I feel it is where the thought of "Claustrophobia" comes from for many people, mostly non-divers, when they see the Pillsbury Doe Boy waddle into the water! Most think or say
"I could do that it's too Claustrophobic!" The freedom of warm water diving is exhilarating in comparison! The challenge is to manage your comfort, your buoyancy, and your equipment that is greater than many are used to! If your involved with really cold now your talking other equipment issues as well, like regs freezing, give me warm water anytime!

 

[Danninella]

Thanks everyone agin on the tips and for a nice discussion. I was not sure about the BC/suit inflator thing, but I guess that in all cases there is the "school book" variants and the "experience" variants of doing things.

I am going to take your tips and use them during my next dives. As I am still in the learning phase (do we ever leave it?) I do my dives so as to learn and gain experience.

About the weighting I think I am (somewhat) correctly weighted. Last time I dumped some weight and it felt good under water, with the one exception that I had a hard time to get under the water.

 

[String]

Struggling a bit to get down that first 2m is normal.

To do a weight just you need just about an empty tank and see if you can hold a stop at 3m depth with little air left in the suit or jacket. Everything else is just guesswork.

 

[dave4868]

I sometimes get the feeling that I am at the surface before being able to the all the right things, like dumping air. It feels like I can´t get the air out fast enough.
My BC is usually empty, I just use the dry suit for bouyancy. Should one use the BC also?

Opinions vary.

My preference for buoyancy control is to use only the drysuit because it's simpler to manage and warmer to have more air in the suit.

Since I also prefer to be moderately overweighted and therefore have even more air in the suit, using only the drysuit makes it easy to vent the amount needed just by a slight raising of the exhaust valve, even when horizontal in shallow water. I don't have to tip toward vertical to get enough air to the exhaust valve.

The drawback of excess air in the suit is the more rapid change in buoyancy as depth changes. The drawback of using only the drysuit for buoyancy control is the slower exhaust valve compared to the BC. I don't find either drawback to be significant, even in the winter when extra insulation means having 50+ lbs of lead. That's a lot of air to exhaust when needed.

Thanks everyone agin on the tips and for a nice discussion. I was not sure about the BC/suit inflator thing, but I guess that in all cases there is the "school book" variants and the "experience" variants of doing things.

I am going to take your tips and use them during my next dives. As I am still in the learning phase (do we ever leave it?) I do my dives so as to learn and gain experience.

About the weighting I think I am (somewhat) correctly weighted. Last time I dumped some weight and it felt good under water, with the one exception that I had a hard time to get under the water.

Sometimes, perfect (minimal) weighting can make it difficult to get the suit to vent that last little bit to stop the ascent.

Some other factors include position and efficiency of the exhaust valve, trapping of air in the legs and elsewhere, and the type of insulation used. These factors can affect whether how fast the suit is able to shift air and allow it to vent through the valve.

If I'm wearing just fleece undergarments, they allow quick venting. If I wear an undergarment with a nylon shell, like my Weezle Extreme Plus, it tends to slow the movement of air to the exhaust valve.

Just curious, when you say sometimes it felt you couldn't get the air out of the drysuit fast enough, was the air rushing quickly out of the exhaust valve or was it a trickle that just didn't happen fast enough. Was it adequate if you were vertical?

Did you wait too long to start venting perhaps? In shallow water it can get ahead of you fast.

Was it shallow water near the end of your dive with a near-empty tank? Was it possible you were underweighted at that point?

Have you determined how close you are to your minimum weighting?

Since you start the dive with the added weight of tank air (about 6.4 lbs for an al80), I'd have to say it should be fairly easy to descend at that point just by venting the suit while vertical with your head up.

Maybe you're slightly underweighted. That makes buoyancy control more difficult, for sure!

Dave C

 

[Bob Vincent]

The more I dove cold water, the more I realize how difficult it is. Doing pool dives with no weights except a steel tank, I can maintain fairly good bouyancy from 13 ft to 4 ft. No trouble, not even have to mess with my BC.

Now wearing double wetsuit (14 mm at the trunk, and 5 mm at the arms and legs), my wetsuit acts like a BC. You constantly have to subtract air as you go shallow, and add air as you go deep. I did a mapping project where we had to go from shallow to deep, and shallow again, and it was a pain.

From that perspective, I would say that the most challenging diving environment is not deep at 120 ft, but shallow diving, where there is constant change in depths when wearing alot of neoprene.

Yes Grasshopper
:rambo:

 

[ucfdiver]

Do you have any really good tips for keeping it cool and regaining control when one feels that one helplessly floats upwards?

bend your knees so it lifts your body up, grab your shins, and do a summer salt in the water. This allows you to recover.

Then learn not to put too much air in the suit. If you're finding yourself going feet up too often, you're using waaaay too much air in the suit. I'm sure you paid for a bcd, use that bcd, don't rig it and use a drysuit for buoyancy.