What would be a safer weight next dive?

[jar546]

I hope you were shown how to do a proper weight check in your ow class. You should have been. You also should know how to determine your weighting requirements for fresh versus salt water. I would also expect them to have explained in detail the difference between steel and aluminum tanks and how to read then markings on them. If not I would question what other BASIC information was left out. Even as a vacation diver you should have the tools and knowledge to know when you need more weight, how to determine that, and how to use the buoyancy characteristics of your tank to adjust that.

Jim, you are a very knowledgeable diver and instructor. She is asking for some assistance but I am starting to see that on many of your posts you go right for the comments about what training they should have had rather than offering assistance. That is not going to help anyone and gives the impression that since you offer classes and author books, you are truly being self serving.

 

[Scuba_chicck]

Hi Jim,
Yes. I was taught how to determine in the pool and then out at sea....I think what's getting lost via the thread is that I had done a hand full of dives at a certain weight that worked very well. I was able to do the cross legged neutral buoyancy float etc. What I don't understand is with the exact same equipment why was the same weight insufficient at the deeper dive. The only conclusion I can come up with after reading the threads is that I was lower in air thru ascent. I hadn't thought 100psi or so would make such a difference but I obviously still have a lot to learn.

 

[g1138]

To be frankly honest Scuba_chick, there's a lot of info missing in this thread which leads us to second guessings.
We're all offering suggestions but unless we know detail for detail what your dive consisted of up until the uncontrollable ascent happened, we can't even say for sure if it was a weighting problem or not.

If you can remember, let us know how your dive went from your descent to your ascent.
Did you have trouble getting down or did you start sinking fast even before you fully deflated.
Did you deflate on ascent?

We can't really make an educated guess without details like this.

 

[Scuba_chicck]

I know, I'm sorry.
I appreciate your help

 

[g1138]

It's ok.
There's plenty of things new divers miss or forget after getting certified.
What's great is that you can ask any questions you have here, and also see what questions others have to ask.
There are things people know they don't know
and things they don't know, they don't know.

Don't worry about this, just learn from it.
In the end what makes a good diver is not how experience you are, but how willing you are to continue learning and helping others to learn as well.

So for starters, learn how to identify your tanks and how much volume capacity they carry.
Also learn how much PSI they can be filled with.
Check to make sure the tanks are within hydro too.
Every tank has a hydro date and manufacter's stamp detailing these things.
It's always on the shoulder of the tank.

 

[jar546]

Don't be sorry. You had a problem and want to fix the problem. You came here for advice because it is very convenient and there are plenty of qualified people that can help you when they have all of the information that they need. There are many variables but weighting and buoyancy are extremely important and I would suggest going back to your OW instructor for guidance and or further assistance with getting your buoyancy and weighting just right.

 

[Scuba_chicck]

Will do.
Thanks.

 

[chrpai]

My tank was just about at 700psi. Thank you for your help, I will certainly try that.

I haven't read this whole thread yet, but has anyone taught you how to do a neutral bouyancy check? Being at the end of a dive with 700 psi is the perfect situation to do this. The goal is to have the correct amount of weight to maintain neutral bouyancy at 10' when you tank is nearly empty and your BCD is fully deflated.

If you have too little weight, you pop like a cork as you describe, if you have too much weight you have to over inflate your BCD contibuting to yo-yo diving and poor trim.

 

[chrpai]

What I don't understand is with the exact same equipment why was the same weight insufficient at the deeper dive.

The only thing you should notice on the deeper dive is you have to inflate your BCD more to compensate for the additional suit squeeze under pressure. Coming out of pressure the suit gives you more bouyance along with the extra air in the BCD and it's very easy to get out of control quick.

Another thing to point out is how relaxed and comfortable you are. You might be doing a 25' blue water dive and be all relaxed but then go on a 90' green water dive and be stressed out. This effects your breathing which is a big part of your bouyancy control. Remember, breath in rise, breath out sink. Well when you are stressed you can have a lot more air in your lungs then you realize. Also because of the stress you might think you let your all of your air out of the BC but maybe you didn't.

I can remember my first dives getting the weight right was hard. That's why instructors and DM's tend to over weight newbie divers. As your skills and awareness improve these problems will go away. An experienced dive buddy will help you get their faster. You already have the education, you just need the experience.

 

[Scuba_chicck]

thank you chrpai, that makes sense - more buoyancy from the suit combined with the BCD air causing a problem that caused uncertainty (questioning my sudden buoyancy) that only increased the problem...extra air in my lungs.
I have been told I look comfortable under the water and I do feel that way...but that day, going for such a deep dive (compared with what I felt prepared for), coached to stay just above the dive master to make my dive slightly shallower and to take shallower breaths to increase my air duration ... perhaps I just ended up with too much air in my lungs.
Thank you