Bruce Justinen
Contributor
Hi, this is Bruce with SEASOFT SCUBA and I have been teaching "PROPER WEIGHTING & BUOYANCY CONTROL" around the country for more than 25 years.
I am going to give you a brief synopsis on how to control your buoyancy while diving.
First of all there are a lot of variables to consider when addressing buoyancy control and the right amount of weight.
The type of exposure suit, neoprene or not, thickness of neoprene, old or new neoprene, trilam or other material, undergarment thickness or material or loft, new or experienced diver, woman or guy, size of tank, tank fill, steel or aluminum, short waisted, tall, in good shape, out of shape, hot day, cold day, depth of dive, fresh or salt, cold or warm water, current or no current, depth of the dive....
As you can see all of the above can and do change the variables on how much weight to wear and what it will take to control your buoyancy during a dive. If you have any specific questions on any of the above you can message me privately. Let's continue.
Let's set up a scenario for a diver. How much weight does he need?
Male, 180 lbs. 5' 9" diving a new 7 mm wetsuit at DUTCH SPRINGS (a popular quarry in Pennsylvania) on May 6, 2019. The forecast is a high of 73 and a low of 55 and it will be mostly cloudy. Water temperature is about 50 degrees. He is a new diver diving a very full aluminum 80 with a negative buoyancy of 3 lbs. The diver has a plate and wing with 50 lbs. of lift and the rest of his gear has just been serviced. How much weight does he need and WHERE should he wear it?
Here are some things we know:
1. The 7 mm suit will be extra buoyant because it is NEW and has not had some of the buoyancy "kicked" out of it by several exposures to depth. After a few dives it will be more comfortable AND not quite as buoyant. This extra initial buoyancy could be as much as 2 lbs.
2. Weather is not going to be a factor but the water is cold for a wetsuit. Really cold. The cold water may increase the divers rate of respiration AND make hypothermia a possible issue. The increased rate of respiration could require a rise in the weight amount required for the dive. This weight amount for this size diver could be 1 to 3 lbs.
3. The aluminum tank is negative by 3 lbs. now but will be positive by about 2 lbs. near the end of the dive THAT is a CHANGE of 5 lbs. to the PLUS side. The diver must account for that. If they are planning on doing a safety stop at the end of the dive they will need to wear enough EXTRA weight to offset the 5 lb. change in buoyancy.
4. The diver is wearing a plate and wing and with this much lift it can feel like he has 3 or 4 volleyballs strapped to his back. It can be very difficult to manage this type of BC initially and as he fights to remain face up on the surface he finds his respiration rate rising rapidly and feels as if he has just run the 100 yd. dash. He finally let's the air out of the BC and finds that his other BC (his lungs) is very full and he takes big gulps of air trying to descend.
5. In futility he rises to the surface again and again only to invert and kick harder and harder to get down while he gasps for air. Finally he aborts the dive while yelling to his buddy "I .... don't ........ have ............ enough .............lead."
So what could he change next time? Let's do it again.
1. He starts with 20 lbs. because that is what his instructor told him would be the right amount. But his instructor told him that because his suit was new that he should planning on going in the water early with 3 or 4 extra lbs. and "test" his buoyancy. "Let all the air out and exhale all your air and kneel down. Make sure your breathing is normal." If you can kneel down easily then you are good to go. If you still kind of float there, add a couple of more lbs."
2. As soon as he enters the water he knows the plan and he gets moving. The water is very cold and a moving diver is going to adapt to the cold a lot easier than a stationary diver.
3. His instructor also taught him to make a safety stop and told him that his tank would become more positive throughout the dive and at the end could be 5 lbs. or more positive than it was at the beginning. "So be prepared for that and make sure you are a little overweight at the beginning or you will not be able to do the safety stop."
4. His instructor tried to talk him into a jacket style BC because they are easier to dive with better buoyancy characteristics but his friend had a plate and wing so he wanted to be like his friend. "Since you bought one go ahead and use it. But don't add any more weight than you need to because they can throw your balance off, especially at the surface."
5. Where does he wear the weights? Today's diver has many options:
A. Ditchable weight pockets mounted on the plate and wing waist straps.
B. A soft stretchable weight belt.
C. A tank weight, a weight belt for your tank (especially helpful to offset the buoyancy characteristics of a P&W).
D. An ankle weight(s) wrapped around the tank valve (a poor man's tank weight).
E. A heavy stainless steel plate to offset some of the weight needed.
F. Our diver did not make this choice but could have chosen a steel tank and received up to 7-8 more lbs. of negative buoyancy at the beginning of the dive. (They still would have lost 5 lbs. of buoyancy during the dive.)
I believe that the following skills are generally not taught and can be such a huge advantage to every diver while trying to descend. There are TWO ways to breath as you descend and I am going to describe the polar opposites of each of them so any diver can see why you would choose B over A.
The A DIVER: The A DIVER is probably a little bit (or more) out of breath from putting his/her gear on, or swimming out or..., they immediately start to descend and they take big lungfuls of air and quickly eject the air from their lungs to quickly grab another lungful. Their lungs are at least 80% full for the entire descent and they probably struggle to do so and they wonder why the first 1,000 lbs. of air went so fast. Notice - SLOW LONG INHALE - QUICK EXHALE!
The B DIVER: The opposite is true of divers who have been taught the following breathing method. As they start to descend they slowly EXHALE their breath and then when they require another breath they quickly inhale and slowly exhale again. They repeat this exercise over and over until they have achieved 6 to 15 feet of depth where there is no longer an issue with the descent. During the descent their lungs were EMPTY 80% of the time and their breathing did not interfere with their buoyancy. QUICK INHALE - LONG, SLOW EXHALE!
When using this breathing skill the diver, when weighted properly, is able to descend with very little effort and the diver is also able to perform a safety stop at the end of the dive. This is what divers want to accomplish, buoyancy that is controlled by the diver and not by an overabundance of lead.
If you have any questions for comments please feel free to contact me here or at bruce@seasoftscuba.com.
I hope this was not too long. Thank you for your patience.
Dive safe,
Bruce
I am going to give you a brief synopsis on how to control your buoyancy while diving.
First of all there are a lot of variables to consider when addressing buoyancy control and the right amount of weight.
The type of exposure suit, neoprene or not, thickness of neoprene, old or new neoprene, trilam or other material, undergarment thickness or material or loft, new or experienced diver, woman or guy, size of tank, tank fill, steel or aluminum, short waisted, tall, in good shape, out of shape, hot day, cold day, depth of dive, fresh or salt, cold or warm water, current or no current, depth of the dive....
As you can see all of the above can and do change the variables on how much weight to wear and what it will take to control your buoyancy during a dive. If you have any specific questions on any of the above you can message me privately. Let's continue.
Let's set up a scenario for a diver. How much weight does he need?
Male, 180 lbs. 5' 9" diving a new 7 mm wetsuit at DUTCH SPRINGS (a popular quarry in Pennsylvania) on May 6, 2019. The forecast is a high of 73 and a low of 55 and it will be mostly cloudy. Water temperature is about 50 degrees. He is a new diver diving a very full aluminum 80 with a negative buoyancy of 3 lbs. The diver has a plate and wing with 50 lbs. of lift and the rest of his gear has just been serviced. How much weight does he need and WHERE should he wear it?
Here are some things we know:
1. The 7 mm suit will be extra buoyant because it is NEW and has not had some of the buoyancy "kicked" out of it by several exposures to depth. After a few dives it will be more comfortable AND not quite as buoyant. This extra initial buoyancy could be as much as 2 lbs.
2. Weather is not going to be a factor but the water is cold for a wetsuit. Really cold. The cold water may increase the divers rate of respiration AND make hypothermia a possible issue. The increased rate of respiration could require a rise in the weight amount required for the dive. This weight amount for this size diver could be 1 to 3 lbs.
3. The aluminum tank is negative by 3 lbs. now but will be positive by about 2 lbs. near the end of the dive THAT is a CHANGE of 5 lbs. to the PLUS side. The diver must account for that. If they are planning on doing a safety stop at the end of the dive they will need to wear enough EXTRA weight to offset the 5 lb. change in buoyancy.
4. The diver is wearing a plate and wing and with this much lift it can feel like he has 3 or 4 volleyballs strapped to his back. It can be very difficult to manage this type of BC initially and as he fights to remain face up on the surface he finds his respiration rate rising rapidly and feels as if he has just run the 100 yd. dash. He finally let's the air out of the BC and finds that his other BC (his lungs) is very full and he takes big gulps of air trying to descend.
5. In futility he rises to the surface again and again only to invert and kick harder and harder to get down while he gasps for air. Finally he aborts the dive while yelling to his buddy "I .... don't ........ have ............ enough .............lead."
So what could he change next time? Let's do it again.
1. He starts with 20 lbs. because that is what his instructor told him would be the right amount. But his instructor told him that because his suit was new that he should planning on going in the water early with 3 or 4 extra lbs. and "test" his buoyancy. "Let all the air out and exhale all your air and kneel down. Make sure your breathing is normal." If you can kneel down easily then you are good to go. If you still kind of float there, add a couple of more lbs."
2. As soon as he enters the water he knows the plan and he gets moving. The water is very cold and a moving diver is going to adapt to the cold a lot easier than a stationary diver.
3. His instructor also taught him to make a safety stop and told him that his tank would become more positive throughout the dive and at the end could be 5 lbs. or more positive than it was at the beginning. "So be prepared for that and make sure you are a little overweight at the beginning or you will not be able to do the safety stop."
4. His instructor tried to talk him into a jacket style BC because they are easier to dive with better buoyancy characteristics but his friend had a plate and wing so he wanted to be like his friend. "Since you bought one go ahead and use it. But don't add any more weight than you need to because they can throw your balance off, especially at the surface."
5. Where does he wear the weights? Today's diver has many options:
A. Ditchable weight pockets mounted on the plate and wing waist straps.
B. A soft stretchable weight belt.
C. A tank weight, a weight belt for your tank (especially helpful to offset the buoyancy characteristics of a P&W).
D. An ankle weight(s) wrapped around the tank valve (a poor man's tank weight).
E. A heavy stainless steel plate to offset some of the weight needed.
F. Our diver did not make this choice but could have chosen a steel tank and received up to 7-8 more lbs. of negative buoyancy at the beginning of the dive. (They still would have lost 5 lbs. of buoyancy during the dive.)
I believe that the following skills are generally not taught and can be such a huge advantage to every diver while trying to descend. There are TWO ways to breath as you descend and I am going to describe the polar opposites of each of them so any diver can see why you would choose B over A.
The A DIVER: The A DIVER is probably a little bit (or more) out of breath from putting his/her gear on, or swimming out or..., they immediately start to descend and they take big lungfuls of air and quickly eject the air from their lungs to quickly grab another lungful. Their lungs are at least 80% full for the entire descent and they probably struggle to do so and they wonder why the first 1,000 lbs. of air went so fast. Notice - SLOW LONG INHALE - QUICK EXHALE!
The B DIVER: The opposite is true of divers who have been taught the following breathing method. As they start to descend they slowly EXHALE their breath and then when they require another breath they quickly inhale and slowly exhale again. They repeat this exercise over and over until they have achieved 6 to 15 feet of depth where there is no longer an issue with the descent. During the descent their lungs were EMPTY 80% of the time and their breathing did not interfere with their buoyancy. QUICK INHALE - LONG, SLOW EXHALE!
When using this breathing skill the diver, when weighted properly, is able to descend with very little effort and the diver is also able to perform a safety stop at the end of the dive. This is what divers want to accomplish, buoyancy that is controlled by the diver and not by an overabundance of lead.
If you have any questions for comments please feel free to contact me here or at bruce@seasoftscuba.com.
I hope this was not too long. Thank you for your patience.
Dive safe,
Bruce
