5 Gallon Pail, Back Inflation & Aluminum, G-O Diving

Your safety or deco stop will be at 10 feet or deeper the water pressure
will compress the suit and undies enough to off set the swing in steel
tanks. If you dive aluminum that's a whole different ball game. But why
would you, With a dry suit you are already positive. Why add more positive
in the easiest place to be negative. Dry suit divers should be using steel
tanks and backplates as primary weight sources. and once again this is only
a starting point. A first dive without proper weight adjustment should be
planed to prevent any deco needs. Starting out neutral and then adding 2 - 5
lbs to ensure the safety stop is a lot easier then blindly strapping on 35
or 40 lbs (5 gal bucket at 8 lbs/gal)of lead and jumping in. If I were to do
that with my gear configuration I would be 40 lbs overweight.


"Al Wells" <al.wells@gmail.com> wrote in message
news:MPG.1fb654e6bf5ceb889898a8@news.verizon.net.. .
> In article <jK%2h.619$AQ6.123@newsfe11.lga>, jcassara@optonline.net
> says...
>> At
>> the point when you enter the water you should of do a weight check. all
>> air
>> out and exhale, you should hang with the water halfway across your face.
>> That would make you neutral at the surface. Then add a pound or two if
>> you
>> descend without a line.
>
> If you do this with full tanks you will be light for your ascent, when
> your tanks are lighter. You need to be able to hold the last deco or
> safety stop. That means you need to be heavy at the beginning of the
> dive by the amount your tanks will swing.

The swing in tank weight is about the same for all tanks. If you use a rule
of thumb that every 10 ft3 of air will lose 1# you'll be about close enough.
If you use an aluminum 80 and suck it dry you'll have 8# less at the end of
the dive. If you use a steel 80 and suck it dry you'll have about 8# less
at the end of the dive. The difference is that the steel tank will probably
still be negative while the aluminum tank probably will be positive.

For my type diving I see no good reason to use aluminum tanks. Their best
quality is they are cheaper to buy.


"John Cassara" <jcassara@optonline.net> wrote in message
news:Lg03h.2198$hr3.98@newsfe08.lga...
> Your safety or deco stop will be at 10 feet or deeper the water pressure
> will compress the suit and undies enough to off set the swing in steel
> tanks. If you dive aluminum that's a whole different ball game. But why
> would you, With a dry suit you are already positive. Why add more positive
> in the easiest place to be negative. Dry suit divers should be using steel
> tanks and backplates as primary weight sources. and once again this is
> only a starting point. A first dive without proper weight adjustment
> should be planed to prevent any deco needs. Starting out neutral and then
> adding 2 - 5 lbs to ensure the safety stop is a lot easier then blindly
> strapping on 35 or 40 lbs (5 gal bucket at 8 lbs/gal)of lead and jumping
> in. If I were to do that with my gear configuration I would be 40 lbs
> overweight.
>
>
> "Al Wells" <al.wells@gmail.com> wrote in message
> news:MPG.1fb654e6bf5ceb889898a8@news.verizon.net.. .
>> In article <jK%2h.619$AQ6.123@newsfe11.lga>, jcassara@optonline.net
>> says...
>>> At
>>> the point when you enter the water you should of do a weight check. all
>>> air
>>> out and exhale, you should hang with the water halfway across your face.
>>> That would make you neutral at the surface. Then add a pound or two if
>>> you
>>> descend without a line.
>>
>> If you do this with full tanks you will be light for your ascent, when
>> your tanks are lighter. You need to be able to hold the last deco or
>> safety stop. That means you need to be heavy at the beginning of the
>> dive by the amount your tanks will swing.
>
>

ben bradlee wrote:

>>snip<<

> For my type diving I see no good reason to use aluminum tanks. Their best
> quality is they are cheaper to buy.

And for a lot of people, that is a concern. I still dive with my double
AL80's. Oh, I have to carry more lead (20lbs in DUI weight and trim
harness) and the backplate is SS as opposed to aluminum with the 98's.
With the 98's, 10lbs.

John Cassara wrote:
> I have to admit I did not read the tread completely but it seams you must of
> carried the full calculated weight needed by the displacement of the
> thermals. You need to also calculate the negative and positive weight
> components that you carry in your gear. Steel tanks are negative by 3 - 7
> lbs. Your regulators gauges reels BCD Plate fins mask etc all contribute to
> your weight and trim needs. Most dry suit divers also wear ankle weights.


That just means they learned to dive a drysuit the lazy way, with a bit
of practice most could do away with the ankle weights.



At
> the point when you enter the water you should of do a weight check. all air
> out and exhale, you should hang with the water halfway across your face.
> That would make you neutral at the surface. Then add a pound or two if you
> descend without a line. If you do use a line then your ready to go, just
> pull yourself down till your soft stuff compresses and your negative. I dive
> a tri-lam with steel doubles reels bags computers canister light etc. I do
> not need any lead. If I leave the light behind I add 5 lbs to my harness and
> all is good.



Your supposed to inflate the drysuit to offset the squeeze, if your
insulation is being compressed you lose insulation.


Do the weight check with 500 psi of backgas and see if you can hang at
15 ft with no gas in your wing, and just enough gas in drysuit to offset
squeeze.



John Mason

John Mason Jr <notvalid@cox.net.invalid> wrote:
>Do the weight check with 500 psi of backgas and see if you can hang at
>15 ft with no gas in your wing, and just enough gas in drysuit to offset
>squeeze.

The 500 psi check is good, but the depth is too much. Do it
this way, and you'll be underweight. First of all, you want to
be able to be neutral at 10 ft, in case you need to make an
actual decompression stop (as opposed to the 15 ft safety stop).
Secondly, you don't really want to bob to the surface. The ideal
would be to be able to do the 30 ft per minute rate all the way
to the surface. On a practical basis, if you start to become
positively buoyant at 5 ft, then your final ascent will probably
be okay.

--
Ron
(user ron
in domain spamblocked.com)

All of the suggestions for the final tuning are correct. The point is to
make fine adjustments typically in the 1 -2 pound range with the now empty
tank to ensure buoyancy control at the end of a dive. The original post was
for the starting point of weight selection. I still say leave the bucket
idea out. Get in the water, set yourself up neutral at the surface add a
couple of pounds and dive. The weight that creates neutral at the surface
will most likely be enough for most to be negative at 10 feet and surely at
15. The additional weight you added from surface neutral is known and will
be the bulk of the weight considered for adjustment changes. If you use clip
on weight or dive with a buddy you can actually remove the weight a pound at
a time while hanging (hand it off to your buddy) for your deco/safety stop
and find the right weight



"Ron" <ron@see.below> wrote in message
news:6jmqk2h4r7nooc2cgsu74anr15l3qgl5h4@4ax.com...
> John Mason Jr <notvalid@cox.net.invalid> wrote:
>>Do the weight check with 500 psi of backgas and see if you can hang at
>>15 ft with no gas in your wing, and just enough gas in drysuit to offset
>>squeeze.
>
> The 500 psi check is good, but the depth is too much. Do it
> this way, and you'll be underweight. First of all, you want to
> be able to be neutral at 10 ft, in case you need to make an
> actual decompression stop (as opposed to the 15 ft safety stop).
> Secondly, you don't really want to bob to the surface. The ideal
> would be to be able to do the 30 ft per minute rate all the way
> to the surface. On a practical basis, if you start to become
> positively buoyant at 5 ft, then your final ascent will probably
> be okay.
>
> --
> Ron
> (user ron
> in domain spamblocked.com)

John Cassara wrote:
snip

>The original post was
> for the starting point of weight selection. I still say leave the bucket
> idea out.

Hi John.

Ben summarized pretty well what I was trying to say about using a
bucket to roughly estimate the weighting needed for drysuit insulation,
but I think we're probably talking about different things at this
point, namely 1) roughly estimating a starting point for weighting and
2) fine-tuning of weighting.

I've tried to carefully describe the _limited_ value of this bucket
approach, but let me add that my purpose in using it is simply to save
a walk back up the beach to add weight or drop off some weight. With a
hundred pounds of gear, that walk gets to be a pain. I'd rather have a
little more than enough weight and be able to drop some in the water,
so the dive could procede.

Also, it's quite rare that this issue comes up; it's not often that one
might change to a significantly different combination of insulation.
You're perfectly right to just get in the water and fine-tune as
needed.

Personally, I've found estimating to be helpful, since I've tended to
experiment a bit with different combinations of insulation for varying
water temps. Since I know what weighting my base insulation requires
(with a certain configuration of gear), I just need to put the added
insulation in the bucket, compress it a bit and estimate what it's
displacement might be. I add that amount of weight and I'm probably
close enough to do the dive and tweak or fine-tune at the end of the
dive. It will almost always start heavy, which saves time.

Now I've got a list of what weighting was needed with the various
combinations of insulation that worked well at different water temps
and activity levels, so I rarely need to estimate.

For me, it's going to come up again this winter because I want to add
some fleece to my thighs, anterior shoulders and possibly armpits, just
to see if that does the trick for low-thirties water temps- just for
fun, to see if that allows a couple hours of warm bliss.

I'd really like to solve the problem of major charlie horses in the
backs of my thighs at the end of a second long cold dive. I hate when
that happens.

I'll take whatever bit of fleece I think might help, ball it up in my
hands and might say, "that looks like about the volume of a 1-gallon
milk container" (or paint can, etc). I'll throw on another 8 pounds of
lead, hire a forklift to haul my ass to the water and do my dive. 8^)

>Get in the water, set yourself up neutral at the surface add a
> couple of pounds and dive. The weight that creates neutral at the surface
> will most likely be enough for most to be negative at 10 feet and surely at
> 15. The additional weight you added from surface neutral is known and will
> be the bulk of the weight considered for adjustment changes.
snip

My preference is to be neutral at the surface with an empty tank and a
little more than the minimum of air in the suit, because I think it's
warmer that way. I don't want to rely on squeeze to get neutral at 10
feet; squeeze on the insulation translates to colder, in my experience.


--
Dave C

PURE TALC - Source, supplier of unscented, oil-free, USP grade PURE
TALC, ideal for use on drysuit latex seals. Offered for sale under eBay
ID dave4868. Thank you!
http://myworld.ebay.com/dave4868

John Cassara wrote:
snip

>The original post was
> for the starting point of weight selection. I still say leave the bucket
> idea out.

Hi John.

Ben summarized pretty well what I was trying to say about using a
bucket to roughly estimate the weighting needed for drysuit insulation,
but I think we're probably talking about different things at this
point, namely 1) roughly estimating a starting point for weighting and
2) fine-tuning of weighting.

I've tried to carefully describe the _limited_ value of this bucket
approach, but let me add that my purpose in using it is simply to save
a walk back up the beach to add weight or drop off some weight. With a
hundred pounds of gear, that walk gets to be a pain. I'd rather have a
little more than enough weight and be able to drop some in the water,
so the dive could procede.

Also, it's quite rare that this issue comes up; it's not often that one
might change to a significantly different combination of insulation.
You're perfectly right to just get in the water and fine-tune as
needed.

Personally, I've found estimating to be helpful, since I've tended to
experiment a bit with different combinations of insulation for varying
water temps. Since I know what weighting my base insulation requires
(with a certain configuration of gear), I just need to put the added
insulation in the bucket, compress it a bit and estimate what it's
displacement might be. I add that amount of weight and I'm probably
close enough to do the dive and tweak or fine-tune at the end of the
dive. It will almost always start heavy, which saves time.

Now I've got a list of what weighting was needed with the various
combinations of insulation that worked well at different water temps
and activity levels, so I rarely need to estimate.

For me, it's going to come up again this winter because I want to add
some fleece to my thighs, anterior shoulders and possibly armpits, just
to see if that does the trick for low-thirties water temps- just for
fun, to see if that allows a couple hours of warm bliss.

I'd really like to solve the problem of major charlie horses in the
backs of my thighs at the end of a second long cold dive. I hate when
that happens.

I'll take whatever bit of fleece I think might help, ball it up in my
hands and might say, "that looks like about the volume of a 1-gallon
milk container" (or paint can, etc). I'll throw on another 8 pounds of
lead, hire a forklift to haul my ass to the water and do my dive. 8^)

>Get in the water, set yourself up neutral at the surface add a
> couple of pounds and dive. The weight that creates neutral at the surface
> will most likely be enough for most to be negative at 10 feet and surely at
> 15. The additional weight you added from surface neutral is known and will
> be the bulk of the weight considered for adjustment changes.
snip

My preference is to be neutral at the surface with an empty tank and a
little more than the minimum of air in the suit, because I think it's
warmer that way. I don't want to rely on squeeze to get neutral at 10
feet; squeeze on the insulation translates to colder, in my experience.


--
Dave C

PURE TALC - Source, supplier of unscented, oil-free, USP grade PURE
TALC, ideal for use on drysuit latex seals. Offered for sale under eBay
ID dave4868. Thank you!
http://myworld.ebay.com/dave4868

Ron wrote:
> John Mason Jr <notvalid@cox.net.invalid> wrote:
>> Do the weight check with 500 psi of backgas and see if you can hang at
>> 15 ft with no gas in your wing, and just enough gas in drysuit to offset
>> squeeze.
>
> The 500 psi check is good, but the depth is too much. Do it
> this way, and you'll be underweight. First of all, you want to
> be able to be neutral at 10 ft, in case you need to make an
> actual decompression stop (as opposed to the 15 ft safety stop).
> Secondly, you don't really want to bob to the surface. The ideal
> would be to be able to do the 30 ft per minute rate all the way
> to the surface. On a practical basis, if you start to become
> positively buoyant at 5 ft, then your final ascent will probably
> be okay.
>

Never had a problem but if you prefer to do the check at 10 ft that's
fine by me

John