neutral without the aid of a BC

[elan]

There are few vintage diving folks on the board that know the physics if that process well. The idea is that you use the weight of the air in the beginnig to counteract the wetsuit buoyancy. Use your lungs for buoyancy and on ascend the fact that the suit does not recompress fully helps to stay not positive on your stop. Some pick up stones before the ascend.

 

[Paladin]

@ nimoh:This question would be best answered in the Vintage Equipment Divers forum, where the practice of diving without a BC is common.

@ chrpai: I began diving 47 years ago, years before the appearance of the first BCs and decades before the "safety stop" was initiated. Divers of my time had to learn dive without BCs, regardless of wetsuit thickness. We had no choice. As far as your complaint about my not doing safety stops is concerned, they are recommended, not required.

Why do you even care that I choose not to use a BC underwater? There are times that I don't even wear one. But that is my choice and you don't have to worry about it. I didn't even own a BC until 2009. Until then, my diving had been solo and in the lakes and rivers close to me. When my sons decided to get into SCUBA, I learned that BCs are required at dive OPs like the quarries used for OW training, so I picked up a new horse collar from Divers Supply, but I didn't change my style of diving just because I now had a BC. Old habits do, indeed, die hard.

I swear, you're worrying this whole concept like a dog worries a bone. It seems like it just tears you up that there are divers out there in the world that do not dive precisely as you dive or think the same way you do. Well, there are plenty of us "rogues" that don't dive like you. Get over it. You dive your way and I'll dive mine.

Now, I'm done with this nonsense. And with you.

 

[nimoh]

@ nimoh:This question would be best answered in the Vintage Equipment Divers forum, where the practice of diving without a BC is common.

@ chrpai: I began diving 47 years ago, years before the appearance of the first BCs and decades before the "safety stop" was initiated. Divers of my time had to learn dive without BCs, regardless of wetsuit thickness. We had no choice. As far as your complaint about my not doing safety stops is concerned, they are recommended, not required.

Why do you even care that I choose not to use a BC underwater? There are times that I don't even wear one. But that is my choice and you don't have to worry about it. I didn't even own a BC until 2009. Until then, my diving had been solo and in the lakes and rivers close to me. When my sons decided to get into SCUBA, I learned that BCs are required at dive OPs like the quarries used for OW training, so I picked up a new horse collar from Divers Supply, but I didn't change my style of diving just because I now had a BC. Old habits do, indeed, die hard.

I swear, you're worrying this whole concept like a dog worries a bone. It seems like it just tears you up that there are divers out there in the world that do not dive precisely as you dive or think the same way you do. Well, there are plenty of us "rogues" that don't dive like you. Get over it. You dive your way and I'll dive mine.

Now, I'm done with this nonsense. And with you.

fairly quickly after starting this post, I realized that it belongs in that forum.

Sounds like an interesting way to dive, and I may try it some time. It sort of puts things in perspective when DIR divers (including me) use the term "minimalist gear configuration"

Now, there I've done it, I've gone and used the dreaded "DIR" that is sure to send this thread running for months in a heated debate

 

[Eric Sedletzky]

I often dive with no BC in cold water wearing a 7mm wetsuit.

How do I do it?
First, the wetsuit I use is a custom made out of a very dense material that minimizes crush.
Second, I weight myself as if I was freediving (allowing for the tank and reg in the equation) so that to decsend I have to do a head first pike and kick down.
Once I reach depth, generally about 30 to 50 feet (in a location with a known depth range) I am just a tad under neutral but can compensate for it by holding a larger volume of air in my lungs. As the tank empties the suit has also compressed more and cooled off making it more negative than at the start of the dive so some of the weigh lost in air volume is actually traded back by the suits loss of bouyancy, but I'm still lighter by a few pounds. At the end of the dive I am already working my way back shallower and at 20 feet or so it becomes hard to stay down, so in that case I may look for a suitable rock to pick up and carry around to offset the lightness until I am ready to come up.
Once at the surface I am light and can float no problem without the aid of a BC.
I also keep my NDL's way within limits so if I need to I can do a direct ascent.
That's about it.

It's a fun way to dive but definitely has it's limitations. I dive with no BC many times to do underwater work in marinas and when I dive vintage. A lot of Southern Califonia lobster divers don't use BC's either.
I have only dove without a BC in cold water locally, but I would love to experience diving with no BC in warm water where the perameters are much broader.

 

[nimoh]

I often dive with no BC in cold water wearing a 7mm wetsuit.

How do I do it?
First, the wetsuit I use is a custom made out of a very dense material that minimizes crush.
Second, I weight myself as if I was freediving (allowing for the tank and reg in the equation) so that to decsend I have to do a head first pike and kick down.
Once I reach depth, generally about 30 to 50 feet (in a location with a known depth range) I am just a tad under neutral but can compensate for it by holding a larger volume of air in my lungs. As the tank empties the suit has also compressed more and cooled off making it more negative than at the start of the dive so some of the weigh lost in air volume is actually traded back by the suits loss of bouyancy, but I'm still lighter by a few pounds. At the end of the dive I am already working my way back shallower and at 20 feet or so it becomes hard to stay down, so in that case I may look for a suitable rock to pick up and carry around to offset the lightness until I am ready to come up.
Once at the surface I am light and can float no problem without the aid of a BC.
I also keep my NDL's way within limits so if I need to I can do a direct ascent.
That's about it.

It's a fun way to dive but definitely has it's limitations. I dive with no BC many times to do underwater work in marinas and when I dive vintage. A lot of Southern Califonia lobster divers don't use BC's either.
I have only dove without a BC in cold water locally, but I would love to experience diving with no BC in warm water where the perameters are much broader.

interesting.

So to be clear, you find a dive site where you can swim down to 30-50 feet, with a bottom grade that permits swimming into shallower areas with ample supply of rocks. Correct?

I don't mean to be a pest, but I have a few questions

How big are the rocks that you generally have to pick up?

How do you hold the rocks (i.e. in your hands, pockets, mesh bag)?

Do you find that you need to pick up more rocks as you get shallower?

Assuming you drop the rocks after surfacing, how do you ensure you aren't dropping the rocks on someone?

lastly, this high-density wetsuit, is it just as warm as a conventional 7mm? wetsuit compression is an issue diving with a BC as well, any thoughts on why high-density wetsuits are not more mainstream? (maybe they are more mainstream and I have just not heard about them)

 

[danpass]

I'm thinking back to Thunderball (it was on tv recently) and noticed for the first time that he didn't use a BC. I don't recall any actors using a BC in the movie yet when they relaxed they didn't shoot up nor plummet down.

I'm trying to remember if he even used a weightbelt. One thing I do recall is wondering how they equalized given the masks they were using. From freediving I have figured out how to almost completely do it without a nose pinch. With the mouthpiece in its challenging but mostly possible.

 

[nimoh]

I'm thinking back to Thunderball (it was on tv recently) and noticed for the first time that he didn't use a BC. I don't recall any actors using a BC in the movie yet when they relaxed they didn't shoot up nor plummet down.

I'm trying to remember if he even used a weightbelt. One thing I do recall is wondering how they equalized given the masks they were using. From freediving I have figured out how to almost completely do it without a nose pinch. With the mouthpiece in its challenging but mostly possible.

Sea Hunt is another one, Mike Nelson didn't have a BC. I have wondered before how exactly he does it, and this thread has been very helpful.

I think I may have to check out Thunderball this weekend too. thanks

 

[Eric Sedletzky]

interesting.

So to be clear, you find a dive site where you can swim down to 30-50 feet, with a bottom grade that permits swimming into shallower areas with ample supply of rocks. Correct?

Yeah that's the basic concept. Around here in Northern California it is very rocky with lot's of interesting terrain composed of huge rocks he size of school busses down to rocks the size of softballs and everything in between.

I don't mean to be a pest, but I have a few questions

How big are the rocks that you generally have to pick up?

How do you hold the rocks (i.e. in your hands, pockets, mesh bag)?

No pest at all, glad to answer questions.
For me and the with the combination I dive I look for rocks in the 3 to 4 pound range, about the size of a half loaf of bread. I generally just pack them around like a runner carrying a football. But that's only towards the last few minutes of the dive if I carry any around at all. Sometimes I choose to grab onto a stand of kelp and use it as an ascent line. Around here we have Bull kelp and each stalk looks like a single rope or cable coming out of it's attachment point on a rock and going straight up to the surface. It's supported by a large air ball on the top of the stipe and out of that gas ball is where the long stringy leaves stem from, that's what you see on the surface. So they make a handy tool to control an ascent.
Other times I have a big fish on my stringer so I may not need to use any added balast at all. It's a very freestyle of diving. Some of the appeal is the 'make due with what you have available' aspect. It makes you be creative and think of stuff on the fly.
One thing about this style is that it is a very high energy, constanty moving type of diving. It's not really appropriate for the sky diver position using a frog kick. I suppose if you were right in the perfect buoyancy zone it could be done but generally a good strong regular scissor kick is used with legs back (not bent at a 90 degree angle) and body positioned or oriented straight or parallel in relation to the direction of travel. If you look at freediving technique that's exactly what this is except the only difference would be you have a very minimal scuba on and you can breathe underwater. It's basically kind of where original scuba started; out of skin diving.

Do you find that you need to pick up more rocks as you get shallower?

Generally not, it's a one shot deal, if at all.

Assuming you drop the rocks after surfacing, how do you ensure you aren't dropping the rocks on someone?

I look for bubbles from below or most of the time I'm solo and divers are really sparse up here.

lastly, this high-density wetsuit, is it just as warm as a conventional 7mm? wetsuit compression is an issue diving with a BC as well, any thoughts on why high-density wetsuits are not more mainstream? (maybe they are more mainstream and I have just not heard about them)

It's probbly warmer being that it's custom cut to fit me exactly. It would be too hard to make a generic high density suit fit a variety of different people plus the material is higher grade meaning more money.
The material is a commercial grade made in Korea (I think). It's some stuff my suit maker had access to for a while that he was using to make commercial urchin diver suits. I decided to give it a shot. It's stiff as hell though, even stiffer than the old Rubatex G-231N which was stiff. This stuff makes G-231 look like ultra stretch!
I don't think I will be getting any more suits made out of this material. I heard of a place in Santa Cruz that can make commercial suits out of other stuff stiffer than LDS suits but not as stiff as my suit so I might give them a try.
I look for a certain cut, I like 2 piece beaver tail old school with stainless twist locks and attached hood.

 

[Paladin]

I use a similar system, though my thickest wetsuit is 5mm, not 7mm, and has less compression deal with. I use a 3/2 or 3mm most of the time because I am not a cold water diver. I basically weight myself to be neutral to just a tad negative at the beginning of the dive and positive (at the surface) at the end of the dive. Like ZKY said, this is not "hover" style diving. It is a dynamic style in that you are on the move pretty much all the time. Sometimes, I just want to find a convenient boulder just to sit and feed the fish or ponder the universe.

I seldom find it necessary to pick up a rock for extra ballast.

I have to chuckle when I think of most divers' attitudes when BCs first came out. They weren't accepted with open arms, to put it mildly.

 

[nimoh]

Yeah that's the basic concept. Around here in Northern California it is very rocky with lot's of interesting terrain composed of huge rocks he size of school busses down to rocks the size of softballs and everything in between.


No pest at all, glad to answer questions.
For me and the with the combination I dive I look for rocks in the 3 to 4 pound range, about the size of a half loaf of bread. I generally just pack them around like a runner carrying a football. But that's only towards the last few minutes of the dive if I carry any around at all. Sometimes I choose to grab onto a stand of kelp and use it as an ascent line. Around here we have Bull kelp and each stalk looks like a single rope or cable coming out of it's attachment point on a rock and going straight up to the surface. It's supported by a large air ball on the top of the stipe and out of that gas ball is where the long stringy leaves stem from, that's what you see on the surface. So they make a handy tool to control an ascent.
Other times I have a big fish on my stringer so I may not need to use any added balast at all. It's a very freestyle of diving. Some of the appeal is the 'make due with what you have available' aspect. It makes you be creative and think of stuff on the fly.
One thing about this style is that it is a very high energy, constanty moving type of diving. It's not really appropriate for the sky diver position using a frog kick. I suppose if you were right in the perfect buoyancy zone it could be done but generally a good strong regular scissor kick is used with legs back (not bent at a 90 degree angle) and body positioned or oriented straight or parallel in relation to the direction of travel. If you look at freediving technique that's exactly what this is except the only difference would be you have a very minimal scuba on and you can breathe underwater. It's basically kind of where original scuba started; out of skin diving.



Generally not, it's a one shot deal, if at all.


I look for bubbles from below or most of the time I'm solo and divers are really sparse up here.


It's probbly warmer being that it's custom cut to fit me exactly. It would be too hard to make a generic high density suit fit a variety of different people plus the material is higher grade meaning more money.
The material is a commercial grade made in Korea (I think). It's some stuff my suit maker had access to for a while that he was using to make commercial urchin diver suits. I decided to give it a shot. It's stiff as hell though, even stiffer than the old Rubatex G-231N which was stiff. This stuff makes G-231 look like ultra stretch!
I don't think I will be getting any more suits made out of this material. I heard of a place in Santa Cruz that can make commercial suits out of other stuff stiffer than LDS suits but not as stiff as my suit so I might give them a try.
I look for a certain cut, I like 2 piece beaver tail old school with stainless twist locks and attached hood.

Thanks for answering my questions, I might look into trying this sometime if I run into a group of divers like you and Paladin

---------- Post Merged at 03:29 PM ---------- Previous Post was at 03:27 PM ----------

I use a similar system, though my thickest wetsuit is 5mm, not 7mm, and has less compression deal with. I use a 3/2 or 3mm most of the time because I am not a cold water diver. I basically weight myself to be neutral to just a tad negative at the beginning of the dive and positive (at the surface) at the end of the dive. Like ZKY said, this is not "hover" style diving. It is a dynamic style in that you are on the move pretty much all the time. Sometimes, I just want to find a convenient boulder just to sit and feed the fish or ponder the universe.

I seldom find it necessary to pick up a rock for extra ballast.

I have to chuckle when I think of most divers' attitudes when BCs first came out. They weren't accepted with open arms, to put it mildly.

It's sort of ironic that there was a push back from most divers regarding introduction of BCs, and now the general consensus is that it isn't possible to dive without a BC