Buoyancy

[Coolrunnings1021]

Hi iam really struggling with buoyancy control and weighting. Iam a big bloke and currently dive in salt water with 19kg. I have weight in my bcd and a weight harness. I constantly feel iam being pushed forwards ie head down when diving and feel like iam faceplanting the floor. Also feel ive got floating legs and need to struggle to keep hroizontal. Also being told by a dive buddy that iam at times practically upright in the water and trying to fin along with my knees bent at 45 degrees. Fairly new to diving and want to know if this is a question of incorrect weighting or need to practice position in the water.

 

[KenE]

This really depends on body shape and where your buoyancy is originating. My buoyancy is in the bum and midsection and therefore a bulk of my ballast is on a weight belt worn a bit low on waist. You may need some ankle weights but this will make you more upright. If you are finding yourself upright and also head down then I would suggest working on trim first then move weight when you can't fix it comfortably in the water. I found myself head down during safety stops and unable to right myself easily. A shift of weight down changed the balance. Still need weight on cam band to offset BC gas at depth which is needed to compensate for suit compression. So, I moved weight from integrated pockets to low waist and fixed the issue. I only explain my situation so you have ideas on how to resolve your issues. They won't be the same in most cases, each body is different, as is equipment.

 

[Morgan00]

Hi iam really struggling with buoyancy control and weighting. Iam a big bloke and currently dive in salt water with 19kg. I have weight in my bcd and a weight harness. I constantly feel iam being pushed forwards ie head down when diving and feel like iam faceplanting the floor. Also feel ive got floating legs and need to struggle to keep hroizontal. Also being told by a dive buddy that iam at times practically upright in the water and trying to fin along with my knees bent at 45 degrees. Fairly new to diving and want to know if this is a question of incorrect weighting or need to practice position in the water.

Hello Coolrunnings,
First off, welcome to the sport! As you get more comfortable in the water I believe you will find that you can shed quite a bit of that weight. I would recommend looking into different breathing techniques. Your lungs are your biggest asset for buoyancy control if you are properly weighted. It is hard to give specific answers that will help you quickly without diving with you. I will say that in general, my experience with instructing is that weight distribution plays a big role in proper trim. This is doubly true when someone requires so much weight. I'm going to ask some questions that may help shed light on the situation. What does is your current BCD? Do you dive aluminum or steel tanks? Do you typically wear an exposure suit and if so, what thickness?

 

[divingdayz]

Hi, Welcome to diving. That sounds like an awful lot of weight despite how 'large' you are. As the poster above said, there are so many factors related to bouyancy. Make a video of yourself in the water to see how your position is. Alos, if possible, try different bits of equipment- wetsuit, BC, fins. It takes time to figure things out correctly. In the meantime, enjoy yourself and be safe.

 

[BRT]

Get a DUI weight harness and put a lot of your weight in it and adjust the shoulder straps longer to get better balance towards your feet.

 

[inquis]

It's very common to be head-up as a preventive measure if the center of mass is closer to your head than the center of volume/buoyancy.

Wetsuit or drysuit? 19 kg of lead is a lot if you're wearing a wetsuit, but you need what you need. There's also interplay with you being head up, requiring extra weight to compensate for the vertical component of your diagonal kicking.

Step 1 is establish the total lead needed. With a FULL tank and empty BC, find how much lead you need so you DON'T sink at the end of a normal exhale, but you will sink if you fully exhale. To that amount, add lead equaling the weight of the gas you'll breath during the dive. One kg of air is 775 bar.liters, so a 12 L tank at 200 bar has about 3 kg of air in it (=12*200/775). Alternatively, you could use a nearly empty tank and not have to make any adjustment for the gas weight.

Make sure you flood your wetsuit before doing this. Also cross your ankles to prevent you from unconsciously finning upward.

If you do the above in a pool, you will need additional lead in salt water equaling 2.5% of your total dry-land weight with gear/tank/everything. (This is based on the average salinity around the world.) If your body weight is ~115 kg, that'll be about 3-3.5 kg.

Step 2 is to distribute the lead you found in step 1. Get horizontal and then freeze / stop moving. If you rotate head down, that's confirmation you need to shift lead lower. Switching from neutral to negatively buoyant fins can take the place of about 0.5 kg of lead.

 

[Nixy]

Diving with excellent buoyancy control is a hallmark of skilled scuba divers. You've probably admired them underwater—how they glide effortlessly, conserve air, and maneuver easily, almost like it's second nature. They observe marine life without disrupting their surroundings. The good news is, you can achieve this level of finesse too! The PADI Peak Performance Buoyancy Specialty course is designed to enhance the buoyancy skills you learned as a new diver and take them to the next level.

This course is open to PADI (Junior) Open Water Divers or higher, starting from 10 years old. It's offered in multiple languages.

Take this course if you want to:

• Improve your buoyancy control
• Dive with less weight
• Reduce your air consumption

During the course, you will learn how to:

• Achieve neutral buoyancy
• Hover effortlessly
• Determine the correct amount of weight to use

 

[jezscuba]

Have you tried a weight & trim check with an instructor?

 

[Coolrunnings1021]

Where should weight be positioned? I dive with a steel cylinder, trilaminate drysuit, i have a fleece undersuit. 15l and a 12l cylinder. Ive tried doing weight checks

 

[happy-diver]

Definitely not in your fins or on your ankles, and if contemplating flooding your wetsuit I would first give up diving
Becuse finning is already quite difficult enough without burdening you legs more and the water in Scotland is cold

halò