Descent difficulty, even overweighted

[DreadnoughtNH]

It does sound like your 7mm wetsuit may be the culprit here. If you can try a different wetsuit maker or a thinner wetsuit (I know, BRRRRR!), it would be good just to rule it out.

 

[rx7diver]

Suggesting ways for a novice diver to force themselves down to wetsuit compression depth while they seem to be underweighted seems like an excellent way for this diver to cork to the surface at the end of the dive.
There clearly is an issue with buoyancy going on. That's what needs to be fixed, before brute-forcing depth with no way to control the ascent.

The suit likely has trapped air in it. The trapped air likely will work its way out at depth during the dive. Moreover, the suit is never as buoyant at the end of the dive as it was at the beginning. None of this is new.

ETA: Doesn't take much depth at all for a suit to compress enough to make a difference.

rx7diver

 

[VikingDives]

Basic Scuba. OP mentions they're doing PADI and possibly PPB -- which is the right course for novices that need to sort out their core skills: buoyancy, trim and finning. Some experience will also resolve this.

You mention UTD. Why not push fun-dies too?

I'm of the mind that open water students should not become open water divers until they have mastered things like buoyancy.

I mention UTD because they are pretty prevalent in CA, and they aren't as fanatical about showing up to courses in a bp/w... If I was the OP, and I'd just bought a bunch of gear, I'd be loathe to go buy more just to take an expensive class. I might be willing to take an expensive course in my current gear though.

There's nothing wrong with findies, or taking ITT for that matter but scuba ain't fun when you are having basic problems after certification. The faster the fix, the more likely the person is to keep diving.

 

[ScubaSquatch]

My 2psi, and I see this a lot with students. You're weighted fine and can probably descend fine, but when your feet start to come up you feel out of control and start to subconsciously hold more air in your lungs and breathe off the top of them. With fuller lungs you stop descending and the issue compounds.

Just a theory though.

 

[rx7diver]

I'm of the mind that open water students should not become open water divers until they have mastered things like buoyancy. ...

"Mastering" will come with experience, I think.

I did my entire 16-week university course (a semester of lecture and pool sessions) without wearing a wet suit at all, and without wearing a BC for much of it. This NAUI/YMCA course required us to skin dive (in a full, hooded wet suit with gloves, mask and snorkel, fins and booties, and dive knife, only) during the open water checkout component that took place in May in an Army Corps of Engineers lake in AR, and it was only then that I began to appreciate how wet suit compression impacts buoyancy.

At the end of that weeklong open water checkout, I had not "mastered" buoyancy, to be sure. But I was well on my way to improving.

That was in 1987.

My daughter (univ junior) went through similar training last spring.

FWIW,

rx7diver

 

[Subcooled]

Hello, there. I have difficulty descending, and I have been trying to solve this problem with my scuba instructor. My next dive with her will be the PADI buoyancy course, but I would like to solve this newbie problem before doing that, if possible.

Here is my situation:

• body weight 165 lbs
• aluminum 80 cu ft tank
• soft lead weights, 22 lbs
• vest-style BCD
• 7mm wetsuit, Henderson Greenprene
• open water, Pacific Ocean, Casino Point, Catalina Island

When I attempt to descend, I deflate the BC and I exhale. My head will submerge, but just a couple of feet below the surface my legs float up, either putting me in a sitting position or in a prone position. I am unable to keep my legs below my body.

Why would you want to descend feet first? For the first 3 to 6 feet it's OK, but don't you want to see where you are going? Prone position, and even head down, are great ways to descend (the former specifically with drysuit). You have fins. Use them. In the days of old people put their head down and lifted their feet to initiate a swimming descent. And many still do. Compression of the suit will then help. The only situation where I descend feet first is zero visibility sites with the possibility of sharp objects on the bottom. Those are much nicer to hit with rubber fins than a belly.

As soon as my legs float up, my descent stops.

Because your buoyancy increases with decreasing compression of the suit.

At that point, I usually grab a buoy line and descend hand-over-hand. But even during this process, my legs insist on putting me in a sitting position instead of a standing position.

If you descend by pulling a buoy line (I use it too sometimes, although rarely), then why are you not doing it in a head down position?
Then you could use your fins, too!

I want to be able to cross my ankles and just sink, like everybody else.

Hmm, actually there is something that I forgot to do on my last few dives: I forgot to remove air in the legs of the suit before entering the water. I may have had a fold in the suit near the ankles. Maybe that's why I had trouble descending.

What say you, please? Is leg buoyancy a known property of Henderson Greenprene, or am I making a common mistake somewhere here?

Thank you for your help.

-Bubba

Some people prefer heavier fins, but this is typical only for drysuit diving.

 

[BRT]

Yes. The suit will compress.

rx7diver

And expand

 

[VikingDives]

"Mastering" will come with experience, I think.

I did my entire 16-week university course (a semester of lecture and pool sessions) without wearing a wet suit at all, and without wearing a BC for much of it. This NAUI/YMCA course required us to skin dive (in a full, hooded wet suit with gloves, mask and snorkel, fins and booties, and dive knife, only) during the open water checkout component that took place in May in an Army Corps of Engineers lake in AR, and it was only then that I began to appreciate how wet suit compression impacts buoyancy.

At the end of that weeklong open water checkout, I had not "mastered" buoyancy, to be sure. But I was well on my way to improving.

That was in 1987.

My daughter (univ junior) went through similar training last spring.

FWIW,

rx7diver

Ok, mastery may have been overstating it.

Having basic control of buoyancy at the end of OW shouldn't be a problem. Having floaty legs and an inability to descend without a mechanical aid isn't what I'd call even marginally qualified for certification as an open water diver.

 

[scubadada]

Hi @Bubba_in_cali

You've received good advice. If you are neutral at your safely stop, you will be 5 lbs negative at the start of the dive with an AL80 due to your gas weight. I can't think of a good reason you shouldn't be able to descend other than trapped air, wetsuit or BC.

I swim down to the reef head first after pulling my butt dump. I'm in a relative hurry as I am solo drift diving in SE Florida and want to hit my reef drop, especially with a brisk current.

 

[RyanT]

but when your feet start to come up you feel out of control and start to subconsciously hold more air in your lungs and breathe off the top of them. With fuller lungs you stop descending and the issue compounds.

I'm going to second this as something to consider. When my buddy started her dive career, she had this problem a lot. We worked through her weighting and often she still wouldn't sink. I asked if she was exhaling, she said yes. As we discovered later, when she was nervous, what she thought was fully exhaling was not. As it turns out, when she thought she was exhaling, she was retaining probably more than 50% of her lung volume. As you begin your descent, take a moment to relax and make sure that you fully exhale.