Overweighted???

[tgphelps]

I am a female, almost exactly the same size as Bella and have the same issue. On my last dive (a shore dive using rental equipment) I told the DM/guide I needed 16 lb. Unbenownst to me he gave me 14 (my bad, I should have counted when I put it on). When I couldn't descend, he gave me another 2, which he slipped into one trim pouch, so I was lopsided. With about 600 psi at the end of the dive, I was on the surface by the time we got back to the dock. All of the responses to Bella's post were helpful, especially the point that it can be really hard to get all the air out of the BC. I make a point to write in my log all the equipment I use, starting and ending tank pressure, how much weight I used and water temperature, so at least I can learn from each experience. The idea of density (actually I think it is specific gravity) may be a factor. The standard for specific gravity is based on fresh water at 4 degrees C. I wonder if warmer water makes us floaters even more likely to float. Any physicists out there?

 

[cool_hardware52]

I am a female, almost exactly the same size as Bella and have the same issue. On my last dive (a shore dive using rental equipment) I told the DM/guide I needed 16 lb. Unbenownst to me he gave me 14 (my bad, I should have counted when I put it on). When I couldn't descend, he gave me another 2, which he slipped into one trim pouch, so I was lopsided. With about 600 psi at the end of the dive, I was on the surface by the time we got back to the dock. All of the responses to Bella's post were helpful, especially the point that it can be really hard to get all the air out of the BC. I make a point to write in my log all the equipment I use, starting and ending tank pressure, how much weight I used and water temperature, so at least I can learn from each experience. The idea of density (actually I think it is specific gravity) may be a factor. The standard for specific gravity is based on fresh water at 4 degrees C. I wonder if warmer water makes us floaters even more likely to float. Any physicists out there?

Well from a pure physics perspective warm water is a bit less dense than cold water so "you floaters" should need ever so slightly "less" ballast in warm water.



Tobin

 

[Twoblues]

After a hiatus of several years, I contracted with a Pompano Bea. dive shop for a refresher course-big mistake- I should have rented tanks and done my dives on the shallow reef-building project just south of Anglin's pier. He insisted I was too weighted, with my 3mm. I kept bobbing up and down! After that I continued diving that week with my experienced-level weighting and instructors take a hike!

 

[BRT]

It seems the "experts" always want you to use less weight. Then they promise to carry a few extra pounds in case you need it. When you need it they sometimes have already given it to someone else they convinced not to carry enough weight. I don't trust them and carry a scales so I can check the weight they give me. I'm tired of swimming down on safety stops.

 

[Frosty]

IF bella was doing her training or was freshly minted OW I'd be saying hey maybe the instructor knows something you don't.
But with more than 50 dives shes had time to work out what she needs. Why on earth would anyone argue unless they diddn\t bring enough lead on board ?
The way I see it with weight--it is wot it is and the diver should know what weight they need
Funny thing is I recently had exactly the opposite issue. I dive 10l steel with 2k and 11.5 ally with 3kg when diving tropical.
But the DM insisted I needed at least 4kg.

 

[Patoux01]

I dive 10l steel with 2k and 11.5 ally with 3kg when diving tropical.
But the DM insisted I needed at least 4kg.

Depending on the tanks, he's correct...

Some tanks are ~2kg negative when empty, a usual s80 is ~1kg positive, so switching from on to the other requires 3kg of lead... Of course you can take less and breathe less in. Point here is not that you're overweighted or whatever, simply that it depends on the tanks.
eg a faber 12l tank is 1kg negative, a s80 is 1kg positive, switching from one to the other requires a 2kg change, not 1 (according to the data I found, which might be wrong)

 

[Nasser]

While it's good to remember what your ballpark weight requirements are, something to keep in mind is that their are several factors that will determine those requirements for any dive... and sorry if I'm rehashing some of the points that have already been mentioned.

- What cylinders are you using steel or aluminum? and what is the capacity?

- Exposure protection... diving dry or wet? not only exposure suit thickness but also the inherent buoyancy in some types of neoprene.. a brand new suit will have different buoyancy characteristics than an old compressed suit. Your equipment... some BCD's have quite a bit of inherent buoyancy while some are neutral or even slightly negative.. and of course there are different backplates (steel or alum.) etc..

- Also are you adding new equipment ? dive lights, cutting tools, reels and spools etc.. ? That affects your total weighting.

- Where are you diving? fresh water or salt water? most people who come here to certain parts of the Red Sea are surprised that they need a little more weight than they thougt because the water is vey salty which creates a little added buoyancy... so even diving in different areas of salt (or fresh) water will have an affect.

- Body composition. Those with a little more fat content in their bodies will need more weight than someone who is smaller or leaner... and don't forget if you haven't been diving for a few months, your body composition can change - either gained or lost fat/muscle.

- Finally, there is of course the level of experience. Those who've been diving for a while are generally more relaxed and less likely to retain extra gas in their lungs when exhaling... which also affects buoyancy and keeps the diver more consistent.

I like to always keep a log of my weighting requirements based on configuration & equipment, body weight, type of cylinders, and where i'm diving. This really helps, especially if I haven't been diving for a few months and it gives me a good staring point. From there I can dial things in a little more over the next few dives.

 

[Patoux01]

- Body composition. Those with a little more fat content in their bodies will need more weight than someone who is smaller or leaner... and don't forget if you haven't been diving for a few months, your body composition can change - either gained or lost fat/muscle.

We're talking 2kg every 20kg of fat compared to not having it, you'd have to be morbidly obese before you need the amount of weights some people are carrying...

Your last point is a dodgy limit. That's like saying "but I like going down with full lungs" and taking a few spare weights.

 

[Octopusprime]

Thanks all for the responses.

My trim is pretty good. As evidenced by video, I am horizontal. I hold my fins and exhale to descend. I am going to try some of the weighting exercises once I am off vacation mode. I did a 100 foot wreck dive today and didn't feel like I was descending too fast. I can't "duck dive down" because I need to look up when I equalize (otherwise the tubes don't open, probably because of the way I'm built, it is what it is)

I think I'm going to tell the weight nazis to chill and wear 16 lbs. When I wear 14 the DM has to hold two for me to do my safety stop with, which can't be fun for her.

On another note, I just did my 35th dive. I've only been diving two months, but I've learned a lot. I'm doing 20 more here in Utila and 30 in Roatan next month. I hope I can get some weight off by then, but if not, I'm just going to keep on I guess with the 16 lbs.

It is what it is.

I agree reed with most here... Forget the weight nazis and dive what you need to get down. One thing I did not see many people talk about is the tank... Do you have your own or rent on boat? Some alum tanks are close to neutral and some are up to 6lbs boyant steel tanks could be 6lbs negative or more depending on size. So if the nazis dives nothing but steal HP 100 or larger they could be 6-12lbs heavier. That could be a swig of almost 12-18 lbs from a 6lb boyant tank to a 6lb negative tank.

But the more you dive you will learn tricks to get the air out of bc, sometimes air will get trapped in wetsuit untill your 5-10ft down. I had a time I was having a hard time getting down on dive 2 same config as dive 1. My buddy looked at me pointing to his head. I had huge air bubble in my hood. Because hood was wet it stuck to my head and I had to burp it, then down I went. I poked a hole in top of hood and never had problem again.

diving is about paying attention to the little things and learning from every dive.

 

[Remy B.]

Every person is build different, I,m 1.72m / 5.6ft and weight 81kg / 178lb, I have muscular legs but I'm bud Light, I had to buy me Heavy fins to get my trim right and be horizontal motionless and I use belt weights, if I used integrated it makes me bud light again in the horizontal position.

I use 16lb, in that is what works for me, if I don't, with 1000psi in my tank and the BCD completely empty I go up like a rocket, and have to kick my self down, if I have 500psi even worse, so 16lb make me end all my dive without any air in my BCD,

What I have found is that the very High Ego / I know it better than every body personality type persons are the ones that tell you, you are overweight you don't know what your are doing, your need less weight, the ones that are not like that, just leave you alone and let you be, if you pay attention you will see what I mean, just with a short conversation and questions you can have an idea how the personality is and how they behave.

use what is good for you, check it by been motionless ( cross your legs and arms ) at your safety stop with 500psi in your tank and nothing or very little air in your BCD if you keep your position just by the breathing in and out, then your are properly weighted IMO, others may have other Technics or opinions but that is the one that worked out for me.