Spectre
Contributor
you're cheating. He's giving full numbers, you're giving empty numbers. Add the 5 lb stage and you're at 33 also.
Weighted STA and 36# Pioneer?
- Thread starter MikeS
- Start date
Please register or login
Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.
Benefits of registering include
- Ability to post and comment on topics and discussions.
- A Free photo gallery to share your dive photos with the world.
- You can make this box go away
you're cheating. He's giving full numbers, you're giving empty numbers. Add the 5 lb stage and you're at 33 also.
Scubaroo
Contributor
I gave full and empty next to each other!
Mike was talking about using additional weight in either the ACB or on a weightbelt - I was pointing out that with WITH my weight in the ACB, I came in under his 33lb - and that depending on his body type (I know I've got some extra body fat that could go back into the environment), he might simply be overweighted to begin with. Of course everyone has different weighting requirements though for their body type and exposure protection.
Spectre
Contributor
Yea, I forgot he was talking about adding more weight...
Bad narcotics... bad.
You calculate bouyency to make sure you can float in the beginning of the dive when you are the most negatively bouyent.
You calculate the weight to be sure you can stay underwater at the end of the time when you are the least negatively bouyent.
Scenario:
Drysuit diver with a twinset of 104's, diving wings/backplate.
If at the end of the dive, you have breathed a double of 104's filled to 3500psi of air (~260cf of gas) down to 500psi (~37cf of gas), you consumed 223cf of gas. A cf of gas is ~.081lbs
Bouyency of a full 260cf of gas is ~(-21)lbs
You will have a swing weight of ~18lbs at the end of the dive
The end bouyency for the gas will be (-3)lbs
Say that the pair of 104's are (-3.5)lb bouyent empty
Manifold, regs, hoses and bands light are another (-5)lbs bouyent
Person is ~2lb bouyent
Drysuit inflated adds ~10lbs (actuall bouyency depends on diver's drysuit fill amount)
wings/backplate is (-5)lbs bouyent
All that ads up to (-4.5) lbs of bouyency at the end of the dive, so you need no additional weight to stay down. Then at the beninning of the dive, you will be (-22.5)lbs negaviely bouyent and so will need wings at least 22.5 lbs capacity.
If you toss in an AL 80 stage and an AL40 of deco gas, at the beginning of the dive, you will be another say (-5)lbs bouyent, you will need wings that are 27.5 lbs in capacity, and end the dive at perhaps (-3.5) lbs of bouyency.
I'm pulling the numbers out of the air and doing quick dirty calculations, but I believe that the general idea is correct. A new drysuit diver (like me) may be more than 10lbs bouyent with the drysuit inflated, and experienced drysuit diver may be less.
You calculate the weight to be sure you can stay underwater at the end of the time when you are the least negatively bouyent.
Scenario:
Drysuit diver with a twinset of 104's, diving wings/backplate.
If at the end of the dive, you have breathed a double of 104's filled to 3500psi of air (~260cf of gas) down to 500psi (~37cf of gas), you consumed 223cf of gas. A cf of gas is ~.081lbs
Bouyency of a full 260cf of gas is ~(-21)lbs
You will have a swing weight of ~18lbs at the end of the dive
The end bouyency for the gas will be (-3)lbs
Say that the pair of 104's are (-3.5)lb bouyent empty
Manifold, regs, hoses and bands light are another (-5)lbs bouyent
Person is ~2lb bouyent
Drysuit inflated adds ~10lbs (actuall bouyency depends on diver's drysuit fill amount)
wings/backplate is (-5)lbs bouyent
All that ads up to (-4.5) lbs of bouyency at the end of the dive, so you need no additional weight to stay down. Then at the beninning of the dive, you will be (-22.5)lbs negaviely bouyent and so will need wings at least 22.5 lbs capacity.
If you toss in an AL 80 stage and an AL40 of deco gas, at the beginning of the dive, you will be another say (-5)lbs bouyent, you will need wings that are 27.5 lbs in capacity, and end the dive at perhaps (-3.5) lbs of bouyency.
I'm pulling the numbers out of the air and doing quick dirty calculations, but I believe that the general idea is correct. A new drysuit diver (like me) may be more than 10lbs bouyent with the drysuit inflated, and experienced drysuit diver may be less.
- Messages
- 1,410
- Reaction score
- 2
- # of dives
1) Your wing should have enough lift to be able to float your rig without you in it. If not, say goodbye to your gear.
2) If you have a wing failure, you should have enough ditachable weight to be able to drop and swim up without the help of the wing. If not, you are overweighted. The first posts clearly looks like the diver is overweighted. Get rid of the STA and/or use a lighter backplate while using a steel tank.
3) Your ditchable weight provides the necessary ballast to overcome the positive swing as the tanks drain. Only drop what you need to become neutral in an emergency. Thats why one shouldn't wear a 30 pound belt. All you need to be able to drop in an AL 80 is 6 lbs. For a 104 it is 8 lbs. Doubles require additional unless you considered a few pounds acceptable to swim up. I would keep that under 10 lbs.
4) A shell drysuit with proper undergarments provide consistent positive buoyancy even in the event of a leak. You don't weigh more in the water if you spring a leak. You still dsiplace the same volume of water. Getting out of the water is another story.
2) If you have a wing failure, you should have enough ditachable weight to be able to drop and swim up without the help of the wing. If not, you are overweighted. The first posts clearly looks like the diver is overweighted. Get rid of the STA and/or use a lighter backplate while using a steel tank.
3) Your ditchable weight provides the necessary ballast to overcome the positive swing as the tanks drain. Only drop what you need to become neutral in an emergency. Thats why one shouldn't wear a 30 pound belt. All you need to be able to drop in an AL 80 is 6 lbs. For a 104 it is 8 lbs. Doubles require additional unless you considered a few pounds acceptable to swim up. I would keep that under 10 lbs.
4) A shell drysuit with proper undergarments provide consistent positive buoyancy even in the event of a leak. You don't weigh more in the water if you spring a leak. You still dsiplace the same volume of water. Getting out of the water is another story.
OP
Dan,
Why are you sorry that you disagree, I'm glad that you are? This turned into a great discussion despite the fact that no one has addressed my original question.
I dont think that Im overweighed, Im just buoyant. But I do have to admit the dry suit thing is new and Ive yet to determine what level of squeeze is appropriate.
I was able to swim up without dropping any weight and no air in the bladder. The problem was staying down At the end of the dive making me believe I needed more weight.
If I am properly weighted, your advice seems contradictory.
Get rid of the STA and/or use a lighter backplate while using a steel tank.
This results in more ditch able weight.
Only drop what you need to become neutral in an emergency. Thats why one shouldn't wear a 30 pound belt.
The way to reduce the weight on the weight belt or in my original case the ACB was to add the weighted STA and heavier plate.
I have to disagree here. To be neutrally buoyant youre weight is equal to the weight of the water you displace. In this context you refers to you and all of your equipment including the drysuit and what its filled with. The volume and hence the weight of the water you displace may be the same with a flooded drysuit but your weight is substantially more if the volume is filled with water rather than air.
Mike
Why are you sorry that you disagree, I'm glad that you are? This turned into a great discussion despite the fact that no one has addressed my original question.
I dont think that Im overweighed, Im just buoyant. But I do have to admit the dry suit thing is new and Ive yet to determine what level of squeeze is appropriate.
I was able to swim up without dropping any weight and no air in the bladder. The problem was staying down At the end of the dive making me believe I needed more weight.
If I am properly weighted, your advice seems contradictory.
Get rid of the STA and/or use a lighter backplate while using a steel tank.
This results in more ditch able weight.
Only drop what you need to become neutral in an emergency. Thats why one shouldn't wear a 30 pound belt.
The way to reduce the weight on the weight belt or in my original case the ACB was to add the weighted STA and heavier plate.
I have to disagree here. To be neutrally buoyant youre weight is equal to the weight of the water you displace. In this context you refers to you and all of your equipment including the drysuit and what its filled with. The volume and hence the weight of the water you displace may be the same with a flooded drysuit but your weight is substantially more if the volume is filled with water rather than air.
Mike
- Messages
- 1,410
- Reaction score
- 2
- # of dives
Mike,
You only need enough air to take the squeeze off. Walk into the water up to your neck and burp the suit completely. Now get out of the water. This is approximately how you should dive the drysuit. You may have too much air in it at this time.
If you burp the suit and don't add to much air, you don't change the displacement all that much if you have a flood. It would be negligible. The displacement your body, the drysuit and undergarments less any unneccessary air shouldn't change. If this is the case, you will not weigh more with a flooded suit.
One thing to recognize is the term "proprer undergarments". Thinsulate is hydrophobic (sp?). The voids in the DUI Ultra suit trap gas but water does not get in. Try and submerge this stuff in a tub sometime and you will see what I mean. The stuff also keeps you warm in a flood unlike most other undergarments.
Assuming you have to much air in your suit, you may actually be overweighted. One would have to see you do this in person. It just seems to me to be a lot of weight. A lighter backplate is used to keep you from being overweighted. You should still carry enough ditchable weight to balance the weight of the gas you carry.
I have no idea of your experience or how comfortable you are in the water, but new divers generally hold extra air in their lungs. They never seem to exhale completely. That changes over time as they get more comfortable.
Maybe you should post some specifics about your size, weight and body type and let someone who deals with a lot of different body types comment on your weighting. It just seems like you carry too much weight based on my experience.
btw, what was the original question?
You only need enough air to take the squeeze off. Walk into the water up to your neck and burp the suit completely. Now get out of the water. This is approximately how you should dive the drysuit. You may have too much air in it at this time.
If you burp the suit and don't add to much air, you don't change the displacement all that much if you have a flood. It would be negligible. The displacement your body, the drysuit and undergarments less any unneccessary air shouldn't change. If this is the case, you will not weigh more with a flooded suit.
One thing to recognize is the term "proprer undergarments". Thinsulate is hydrophobic (sp?). The voids in the DUI Ultra suit trap gas but water does not get in. Try and submerge this stuff in a tub sometime and you will see what I mean. The stuff also keeps you warm in a flood unlike most other undergarments.
Assuming you have to much air in your suit, you may actually be overweighted. One would have to see you do this in person. It just seems to me to be a lot of weight. A lighter backplate is used to keep you from being overweighted. You should still carry enough ditchable weight to balance the weight of the gas you carry.
I have no idea of your experience or how comfortable you are in the water, but new divers generally hold extra air in their lungs. They never seem to exhale completely. That changes over time as they get more comfortable.
Maybe you should post some specifics about your size, weight and body type and let someone who deals with a lot of different body types comment on your weighting. It just seems like you carry too much weight based on my experience.
btw, what was the original question?
OP
Dan,
You only need enough air to take the squeeze off.
Unfortunately squeeze is a relative thing, theres squeeze thats bearable and theres squeeze that makes one a soprano.
Thinsulate is hydrophobic.
The underwear I have is Andys US 200. It is three layered, Tactile Ultrex Nylon, Thinsulate, and Polartec. When I went to the pool, I did not use the underwear as I thought I would die of heat exhaustion, the underwear is rated for 28 to 55 degrees and the pool is 84. In the pool with the standard backplate and a PST HP120 tank was neutral with no air in the BC in the shallow end with <300 psi and 10 pounds in the ACB, this is the same weighting as with my 2.5 mil wetsuit. I was also not wearing a hood or gloves.
At Mt. Storm where the temperature was in the fifties, I added a hood, 5-mil wet gloves, and the underwear. On the last dive, I had 26 pounds in the ACB pockets. At the safety stop with 1000 psi I had to hold onto the bottom to stay down. Im guessing that another four pounds would put me where I should be. However, it may be that my drysuit is over inflated.
The underwear is substantial; it looks like a snowmobile suit without a hood. At this point, Im not sure if the underwear requires that much additional weight, twenty pounds, to be added or am I over inflating.
I have no idea of your experience or how comfortable you are in the water, but new divers generally hold extra air in their lungs. They never seem to exhale completely. That changes over time as they get more comfortable.
If I was any more relaxed in the water I would be asleep. I just seem to be buoyant, with or without exposure protection and/or SCUBA.
Maybe you should post some specifics about your size, weight and body type and let someone who deals with a lot of different body types comment on your weighting.
In my admittedly limited experience, this is not something you can do over the Internet. In fact this is one of my pet peeves; I wish I had a dollar for every underweight diver Ive seen that was trying to impress people with how little weight they needed now that they were experienced, only to have to hold on to the anchor line to make a safety stop. Hey, your buoyancy is what it is and theres not much if anything you can do to change it. Whats important is to measure it and be properly weighted. Admittedly, when youre first learning to dive the feet and hands get going every which away which masks buoyancy and you tend to breath with full lungs but it doesnt take long to get past that.
btw, what was the original question?
The original question was attempt putting the new parts (Fred-T plate and STA) together with the Pioneer wing for the first time. It looks simple enough, just bolt the STA to the plate with the supplied bolts with the bladder sandwiched in-between .. Is it that simple?
Did it last night and it was that simple.
Mike
You only need enough air to take the squeeze off.
Unfortunately squeeze is a relative thing, theres squeeze thats bearable and theres squeeze that makes one a soprano.
Thinsulate is hydrophobic.
The underwear I have is Andys US 200. It is three layered, Tactile Ultrex Nylon, Thinsulate, and Polartec. When I went to the pool, I did not use the underwear as I thought I would die of heat exhaustion, the underwear is rated for 28 to 55 degrees and the pool is 84. In the pool with the standard backplate and a PST HP120 tank was neutral with no air in the BC in the shallow end with <300 psi and 10 pounds in the ACB, this is the same weighting as with my 2.5 mil wetsuit. I was also not wearing a hood or gloves.
At Mt. Storm where the temperature was in the fifties, I added a hood, 5-mil wet gloves, and the underwear. On the last dive, I had 26 pounds in the ACB pockets. At the safety stop with 1000 psi I had to hold onto the bottom to stay down. Im guessing that another four pounds would put me where I should be. However, it may be that my drysuit is over inflated.
The underwear is substantial; it looks like a snowmobile suit without a hood. At this point, Im not sure if the underwear requires that much additional weight, twenty pounds, to be added or am I over inflating.
I have no idea of your experience or how comfortable you are in the water, but new divers generally hold extra air in their lungs. They never seem to exhale completely. That changes over time as they get more comfortable.
If I was any more relaxed in the water I would be asleep. I just seem to be buoyant, with or without exposure protection and/or SCUBA.
Maybe you should post some specifics about your size, weight and body type and let someone who deals with a lot of different body types comment on your weighting.
In my admittedly limited experience, this is not something you can do over the Internet. In fact this is one of my pet peeves; I wish I had a dollar for every underweight diver Ive seen that was trying to impress people with how little weight they needed now that they were experienced, only to have to hold on to the anchor line to make a safety stop. Hey, your buoyancy is what it is and theres not much if anything you can do to change it. Whats important is to measure it and be properly weighted. Admittedly, when youre first learning to dive the feet and hands get going every which away which masks buoyancy and you tend to breath with full lungs but it doesnt take long to get past that.
btw, what was the original question?
The original question was attempt putting the new parts (Fred-T plate and STA) together with the Pioneer wing for the first time. It looks simple enough, just bolt the STA to the plate with the supplied bolts with the bladder sandwiched in-between .. Is it that simple?
Did it last night and it was that simple.
Mike
- Messages
- 1,410
- Reaction score
- 2
- # of dives
Just walk into the water but don't submerge your head. If you burp all the air out, that is what you are looking for. You are not looking to sing soprano. It usually takes me about 20 feet of depth before I consider adding gas to the suit.
Mind you, you should still be able to reach your valves. If you can't after burping the suit, you have other problems. Thats another subject. I'm not familiar with your undergarments or suit, so commenting online doesn't mean anything.
I don't know if you have taken a Fundamentals class, but everyone seems to take weight off when the instuctors are through with them. A lot of weight. I'm not sure any of the 12 people got through unscathed when I took the class in March 2002 at Gilboa. Mike Kane could probably vouch for that as well as Brandon and Scott. I think all three are on the board. I'm sure Mike, Andrew and Sonya will do the same to the new students in the May 2-4 class at Gilboa. I get to watch and probably video the class. That and pick up Mike at the airport and drop him off. Hey, I'm not even an intern and I feel like a gopher already.
Mind you, you should still be able to reach your valves. If you can't after burping the suit, you have other problems. Thats another subject. I'm not familiar with your undergarments or suit, so commenting online doesn't mean anything.
I don't know if you have taken a Fundamentals class, but everyone seems to take weight off when the instuctors are through with them. A lot of weight. I'm not sure any of the 12 people got through unscathed when I took the class in March 2002 at Gilboa. Mike Kane could probably vouch for that as well as Brandon and Scott. I think all three are on the board. I'm sure Mike, Andrew and Sonya will do the same to the new students in the May 2-4 class at Gilboa. I get to watch and probably video the class. That and pick up Mike at the airport and drop him off. Hey, I'm not even an intern and I feel like a gopher already.
I've done the math and that's why I'm questioning what this instructor is saying to me. For the sake of clarity, let me re-iterate precisely what his concern is though:
The instructors issue is not with being able to float at the beginning of the dive, but being able to float with enough freeboard (that is to say, with enough of your head / neck / etc out of the water) that communication, easy breathing, etc. is possible in swells and chop.
He says that you can probably gasp for breath with a 40-60lb wing, but if you want to be able to comfortable breathe and possibly be able to help another diver who is having a problem you're going to need more lift.
The way I see it -- with a 60 lb wing I should have no trouble keeping my head and neck out of the water. My experience however is limited to using the shop gear (which is all 80 or 100 lb wings).
I'm trying to decide what wing to purchase. This particular shop says Halcyon is a no no (I suspect for commercial reasons -- they're not a Halcyon dealer), so in the interest of maintaining my relationship with them I'm considering a non-bungied OMS wing. These guys have been very good to me, so I'd like to cooperate with them within reason.
The instructors issue is not with being able to float at the beginning of the dive, but being able to float with enough freeboard (that is to say, with enough of your head / neck / etc out of the water) that communication, easy breathing, etc. is possible in swells and chop.
He says that you can probably gasp for breath with a 40-60lb wing, but if you want to be able to comfortable breathe and possibly be able to help another diver who is having a problem you're going to need more lift.
The way I see it -- with a 60 lb wing I should have no trouble keeping my head and neck out of the water. My experience however is limited to using the shop gear (which is all 80 or 100 lb wings).
I'm trying to decide what wing to purchase. This particular shop says Halcyon is a no no (I suspect for commercial reasons -- they're not a Halcyon dealer), so in the interest of maintaining my relationship with them I'm considering a non-bungied OMS wing. These guys have been very good to me, so I'd like to cooperate with them within reason.
Similar threads
