New DMT, carrying extra weights is really affecting my buoyancy. Help!

[T.C.]

Thank you Jim. Wondered that from the start of reading this.

Do a proper weight check. Then you don't need extra lead. And the students become better.

 

[dvdcssm]

Being overweighted as you are, there is a learning curve. Don't expect it to be the exact same as your normal weighting. You will need more input/output of air at those moments. But it should be intuitive by feel. If it's not you need to work on that part of bouyancy on your own time with your correct weighting. Because in that case, you still don't fully understand it.



Unless you're holding constant depth, that's how you're suppose to operate during a dive.
I touch my inflator and dumps every time I make a 1m depth change and hold. A much more relaxing option rather than relying solely on lung volume to control your bouyancy.

You should keep with three on your belt and 2 in your pockets. Handing off the pocketed weights to needing students/customers.
Better option would be to do a bouyancy check and hand off weights BEFORE the dive begins. After your initial dive, all students should be good to go.

Part of being in the leadership rating of DM, Instructor, and AI is having this knowledge. Become familiar with bouyancy checks and the different results you're looking for when doing one with a St tank and an Al 80 tank. This is both familiarity with yourself and when evaluating other people.
Additionally be familiar with noticing when someone isn't dumping air on ascent, that way you won't make the HUGE/COMMON mistake of over-weighting students, thinking they're under weighted even after loading them with 5 or more kilos.

Weight your students before the dive begins, and you won't have to weight yourself off your norm on the majority of dives.
Worst case scenario, you hand off one weight and be trimmed off center for the dive. Not the end of the world, should only cause an annoyance.


If you can't control your bouyancy with those extra weight because you're not touching your inflator (that's normal). Touch your inflator. Give it some input and output.
If you still can't control your bouyancy, I suggest you have some work to do before you continue your DM.

Thanks for your input, appreciate it. I've only just finished my rescue and started the DM. I have unlimited diving and can take the course at my own pace, so plenty of time for practice and perfecting. I wouldn't take out customers if I wasn't confident in myself, which is why I'm trying to iron out any issues now.

 

[Colliam7]

Well all I really know is that buoyancy is fine using two/three weights and problems arise when I put on the two extras. I need to add air to my bcd so I don't descend, but it never feels 'right', and I have to adjust the amount of air during different parts of the dive. I don't understand how I can 'do it' one minute, then as soon as the extra weight is added I can't. To clarify, I'm not all over the place with five weights, but I can't maintain the same level control and composure I have with three. How do you adapt to diving with a ton of weights?

Several thoughts occur to me:

1. Many DMT / DMCs are still refining their buoyancy / trim. They are better than the average recreational diver, but not as good as the more experienced / long time DMs and instructors. I know I was still fine tuning my buoyancy control when I was a DMC. So, I think it is fair to cut you a little slack and say your buoyancy control overall is still a 'work in progress', and adding weight presents a complication that you will have to learn to overcome;

2. Although probably an unintended outcome, you are actually being exposed, first hand, to the struggles that many OW students have when they are intentionally over-weighted by their instructor, for convenience. You will have a much greater level of empathy for over-weighted students in the future;

3. The extra weight you are carrying is actually a not insignificant amount, RELATIVELY. You describe being comfortable, for much of a dive with 1600g, and having no problems with 2400g. Your optimal weight is therefore probably ~2000g - somewhere between 2 and 3 weights as you describe it. To then add an additional 1600g is a big percentage change (80%), and I am not surprised that it presents a new learning curve to you - it might have for me at that stage in my development. So, while the absolute amount of weight may seem modest, the relative change is considerable. In part, your ability to master the situation is a really matter of practice, over time;

4. One important question to consider what the added weight is doing to your trim. If you are wearing a belt to begin with, and you put the extra weight in your BCD pockets, I am going to guess that the excess weight may be pulling your lower body (legs / feet) down, so you are now possibly swimming at closer to a 45 degree angle than horizontal. This is something else that newer divers routinely seem to experience - they use finning to keep themselves at a level depth while swimming (without realizing they are doing so - the force vectors of each fin stroke are both horizontal and vertical). When they stop finning, they sink, so they add air to their BCD. When they start finning again, they begin to ascend, and have to purge air from their BCD - it becomes an endless, and very frustrating cycle. One solution for you is to change the location of the added weight, to move the weight up, away from the lower body. We often use clip on weights and clip them to a shoulder D-ring. We also use ankle weights (two of which together provide ~1500g) which we also clip to a high point on the harness. I have not seen you in the water, so this is speculative. Ask the instructors you work with to assess your trim, while carrying the extra weights.

 

[DivemasterDennis]

Jim is not answering the question. The fact is most DM's at dive destinations carry and extra weight or two as well. It is a fact,that is part of being a working DM leading casual recreational divers, and it is a good idea for a DM to be able to dive with a few extra pouinds, because often you will need to pass them to another diver. The you have to adjust your buoyancy again. The location of the weights won't change the buoyancy issue. dvdcssm is experienceing what all overweighted divers do: that being overwieghted makes buoyancy control harder because there is more air in the bcd, and it changes volume with even the slightest depth change and that throws off buoyancy. Diving with extra weights is a skill that, like other skills, requires practice and repetition to master. Hang in there.
DivemasterDennis

 

[dumpsterDiver]

Several thoughts occur to me:



3. The extra weight you are carrying is actually a not insignificant amount, RELATIVELY. You describe being comfortable, for much of a dive with 1600g, and having no problems with 2400g. Your optimal weight is therefore probably ~2000g - somewhere between 2 and 3 weights as you describe it. To then add an additional 1600g is a big percentage change (80%), and I am not surprised that it presents a new learning curve to you - it might have for me at that stage in my development. So, while the absolute amount of weight may seem modest, the relative change is considerable. In part, your ability to master the situation is a really matter of practice, over time; .

The relative change in lead ballast is NOT the issue. The problem arises from the mass of excess lead! If you wear no lead and add 5 lbs will there be a 5 zillion percent increase in lead carried and will it cause you terrible trouble? But the diver who carries 35 lbs of lead adding 5 lbs will have no problems?

The diver just needs to practice divin with a belt that has an extra 5 kilos on it in shallow water (or maybe it would be safer to wear a second belt with the extra lead). It just takes time to learn to manage the larger bubble...

 

[Colliam7]

The relative change in lead ballast is NOT the issue. The problem arises from the mass of excess lead! If you wear no lead and add 5 lbs will there be a 5 zillion percent increase in lead carried and will it cause you terrible trouble? But the diver who carries 35 lbs of lead adding 5 lbs will have no problems?

Nope, not the case. It IS part of the issue. A diver who wears 35 lbs, and adds 5 lbs, will notice a change, but not as much as the diver who normally wears 6 (and is used to 6) and then adds 6. Yes, the total amount of weight matters. But, in this case, telling the OP that the absolute amount of change is minimal, and shouldn't be a problem, is simply nonsense.

Now, I fully agree with your second point - the OP needs to practice with the added weight, to get used the the effects of the relatively large relative change in the weight they are carrying. Personally, i believe the bigger issue is quite likely to be related to the effect of carrying extra weight on their trim - something I see all too often in (overweighted but, more importantly, improperly trimmed) OW divers.

 

[daz88]

Experience.....you really should get more before DMT. If you had the experience, you wouldn't need to ask. And carrying 2 extra weights wouldn't be a problem.

 

[japan-diver]

I have to agree that before one is in a DM class carrying extra weight should not be a problem. But the next question is why are you not asking your instructor who is in the water with you and has the best insight into your specific issue? If the instructor(s) of the shop you are taking the class with can not address this simple skill fix what are they really going to teach you?

 

[victor]

DVDCSSM
If you are having issues with 2 extra weights, are you comfortable that all your other skills are up to the standards expected of a DM. Given that you are diving with 2kg I am assuming that you are in tropical waters, and mostly benign conditions.
Your status shows less than 50 dives, how many of these will be in courses or is it just incomplete?
You mention that you have unlimited diving, take a week of your course and dive daily with 4 or 5 kg untiul you are comfortable.
Have a good hard look at the skills you have to posses to be a good DM and decide if you will be able to meet this criteria or if you need some more time in the water with a mentor before coming up to scratch.

 

[scubadiver888]

Hi dvdcssm,

Reading your initial post I see that you had 2 x 800g weights and had great buoyancy for 75% of the dive. It seems obvious to me that the last 25% of the dive was a problem because you lost the weight of your air. Adding the additional 800g weight problem meant that you lost 800g of air on a dive. So starting the dive with 3 weights meant you were 800g too heavy for neutral buoyancy. This was necessary because you HAVE TO start a dive a little too heavy. As you use your air you will change your buoyancy. Realistically, if you had a freeflow, lost all your air and had to go onto your buddy's octo you still want to remain neutral or negatively buoyant. The worst time to be too light would be in an emergency situation. So you are wearing 2.4kg of weight.

One cubic foot of air is going to weight around 35g. So if you are diving an AL80 you have 77.4 cu.ft. of air or 2700g of air. So you should be 2.7kg negatively buoyant at the start of a dive. Could a cylinder have more or less than 77.4 cu.ft.? Sure. Is it precisely 2.7kg? Not really. Is your gauge 100% accurate 100% of the time? Absolutely not. So it is better to be slightly too heavy rather than not heavy enough. If you wear no weights with a full tank can you sink? You should be able to add just enough weight to sink (not swim down but SINK). Now add the weight of the air in the tank. This way, if you have a freeflow and your tank is EMPTY you will still be able to stay down. You don't want to be pushing NDL and have to surface without a safety stop. So you should be able to handle buoyancy swings of +/- 3kg.

If you are an individual diver, responsible for your own safety then you can assume you will never be in a situation where you have no air left in your tank (risky assumption but there is no scuba police). However, as a dive professional who will be in the water a LOT more than your average diver it shouldn't be a matter of *IF* something goes wrong but more when something goes wrong. I'd like to hope I'll be diving until I'm well into my sixties (actually I'll be happy if I'm diving well past that).

Now maybe you are lucky to be diving in tropical waters but for me I dive in 45F/7C water. I wear a 7mm wetsuit with a 7mm tunic plus gloves, hood and boots. As I go deep my neoprene compresses. I have to add air to my BCD to compensate for that. As I go up and my neoprene expands I have to dump air from my BCD. Making these constant adjustments just comes naturally.

When I first started diving 12 years ago it was an effort. Now I don't even think twice about the changes in buoyancy. Change in depth requires me to adjust my buoyancy (add/dump air to keep myself neutral). As I breath down my gas I need to dump a little air from my BCD. I don't even think about this. I don't even realize I'm doing it. I don't breath my air down too quickly. So the adjustments will be small and gradual. I don't change my depth too rapidly. So those adjustments are gradual as well. With practice this should be the same for you.

I also don't carry extra weight for my students. They are taught to be properly weighted. So I don't need to carry weight for when they find themselves too light.