Snorkeling Fin Advice

> I've also seen poor swimmers dive, and think it's a bad idea.]

Me too.

chilly wrote

> I rarely add any air to my BC either. The exception to this "rule" is
> when
> I'm getting deep on a deep dive.

When you dove with us, you were wearing a wetsuit even in our warm waters,
right? While I do compensate for gas use by altering breathing patterns, I
don't, and probably can't compensate for wetsuit compression the same way.
In my neutral configuration, without added issues like wetsuit compression,
it's relatively easy to compensate for roughly 2 lbs of plus or minus
buoyancy during a dive. There may be people who can do it, but adding an
estimated 2 lbs or so of shift due to wetsuit compression, makes adjusting
by breathing patterns alone more effort than it's worth to me and, perhaps,
impossible.

Lee

"Lee Bell" <leebell@ix.remove.netcom.com> wrote in message
news:V2VZd.5787$qf2.684@newsread2.news.atl.earthli nk.net...
> chilly wrote
>
> > I rarely add any air to my BC either. The exception to this "rule" is
> > when
> > I'm getting deep on a deep dive.
>
> When you dove with us, you were wearing a wetsuit even in our warm waters,
> right?

Yes, and always do.

> While I do compensate for gas use by altering breathing patterns, I
> don't, and probably can't compensate for wetsuit compression the same way.
> In my neutral configuration, without added issues like wetsuit
compression,
> it's relatively easy to compensate for roughly 2 lbs of plus or minus
> buoyancy during a dive. There may be people who can do it, but adding an
> estimated 2 lbs or so of shift due to wetsuit compression, makes adjusting
> by breathing patterns alone more effort than it's worth to me and,
perhaps,
> impossible.

Are you saying that's why I may find myself adding a bit of air towards the
bottom of a deep dive?

>
> Lee
>
>

>
> I gave that up long ago as incompatible to efficient fin-swimming.
> I can swim miles without breathing hard with fins, long or short.
> Besides my kick cycles are too slow for finless swim, my legs
> sink. When I started my scuba training, the hardest thing was
> to swim 200 yards WITHOUT fins before one is qualified to take
> the scuba course. I was completely exhausted by 100 yards and
> had to struggle for dear life for the next 100.
>
> I always thought, and still think, that's the SILLEST requirement
> for scuba divers who ALWAYS dive with fins! If the initial
> qualifying "test" had been to swim 800 yards WITH fins, I would
> have done it in 8 minutes, have lunch, and come back to see the
> rest of the trainees finish the same distance. :-))
>
> -- Bob.
>

Bob,

I believe (at least in some regions) there is an alternative test with
fins - 300m from memory although may well have misremembered the
disctance - believe it or not - I may be wrong. Pretty sure on the
alternative approach though, just unsure of the distance. I have seen
very few operators who bother with it though so remains a techicality.

My personal view is that if you can't swim you should not dive. Reasons
too numerous to relate.

Cheers

Simon

Rosalie B. <gmbeasley@> wrote:

>My main
>problem with buoyancy is that I am EXTREMELY buoyant. I can't
>practice in a pool very well because the main problem I have is of
>getting down past 30 feet. Once I'm down there, I do OK, but to get
>down is a problem for me.
>
>My first scuba experience was a very long time ago (January of 1968)
>and at that time we had to go down to the bottom of a pool and take
>our gear off and put it all back on again. I was wearing about 20 lbs
>of weights (and also a wet suit that I had borrowed because this was
>an outdoor pool - even in Key West it's cold outdoors at night in
>January), and I still couldn't go down and sit on the bottom. (We
>didn't have BCDs in those days of course.) The instructor finally
>took off his weight belt and put it across my legs, otherwise he had
>to keep pulling me down to the bottom.

That's air in your lungs causing that bouyancy. Solid tissue
(whether it's bone, muscle, or fat) doesn't have anywhere near
that amount of bouyancy. (It's also why when you get down below
one atmosphere you lose bouyancy, as the air becomes more dense).
[Unless you have football-sized sinuses, that is]

He could also have given you a solid punch to the solar plexus to make
you stay down, but I suppose that could have been rather more permanent.

If you ever want to do it again, practice holding your breath with
a relaxed expiration of your lungs.
--
Ken Tough

Ken Tough <ken@objectech.co.uk> wrote:

>Rosalie B. <gmbeasley@> wrote:
>
>>My main
>>problem with buoyancy is that I am EXTREMELY buoyant. I can't
>>practice in a pool very well because the main problem I have is of
>>getting down past 30 feet. Once I'm down there, I do OK, but to get
>>down is a problem for me.
>>
>>My first scuba experience was a very long time ago (January of 1968)
>>and at that time we had to go down to the bottom of a pool and take
>>our gear off and put it all back on again. I was wearing about 20 lbs
>>of weights (and also a wet suit that I had borrowed because this was
>>an outdoor pool - even in Key West it's cold outdoors at night in
>>January), and I still couldn't go down and sit on the bottom. (We
>>didn't have BCDs in those days of course.) The instructor finally
>>took off his weight belt and put it across my legs, otherwise he had
>>to keep pulling me down to the bottom.
>
>That's air in your lungs causing that bouyancy. Solid tissue
>(whether it's bone, muscle, or fat) doesn't have anywhere near
>that amount of bouyancy. (It's also why when you get down below
>one atmosphere you lose bouyancy, as the air becomes more dense).
>[Unless you have football-sized sinuses, that is]
>
>He could also have given you a solid punch to the solar plexus to make
>you stay down, but I suppose that could have been rather more permanent.
>
>If you ever want to do it again, practice holding your breath with
>a relaxed expiration of your lungs.


And at the time I took the scuba class in 1968, I was wearing a wet
suit top (borrowed from a friend's husband - I don't know how thick),
and 20 lbs of weights. I was 5 months pregnant, but not overweight.
I guess I weighed about 145-150 lbs and was 5'7". Before pregnancy I
had a 24" waist.

Yes, I could make myself sink a little by exhaling, but I still
floated vertical with my head out of the water.

About 10 or 15 years later, I was testing a life saving class that
someone else had taught and due to some technicality, he could not
issue the cards so he asked me to do it. I wanted to be sure that all
the students actually had the skills, so I had each of them save me
and tow me around the pool. One of the guys commented to me as he was
towing me around that towing me was like having his own floatation
device. At that time I weighed about 180 lbs.

I did flunk one of the students - a high school athlete who panicked
when I got him in a front head hold. His mom claimed that was sexual
harassment. My response was - he's only going to save other men?


grandma Rosalie

Thus spake Ken Tough <ken@objectech.co.uk> :

>Rosalie B. <gmbeasley@> wrote:
>
>>My main
>>problem with buoyancy is that I am EXTREMELY buoyant. I can't
>>practice in a pool very well because the main problem I have is of
>>getting down past 30 feet. Once I'm down there, I do OK, but to get
>>down is a problem for me.
>>
>>My first scuba experience was a very long time ago (January of 1968)
>>and at that time we had to go down to the bottom of a pool and take
>>our gear off and put it all back on again. I was wearing about 20 lbs
>>of weights (and also a wet suit that I had borrowed because this was
>>an outdoor pool - even in Key West it's cold outdoors at night in
>>January), and I still couldn't go down and sit on the bottom. (We
>>didn't have BCDs in those days of course.) The instructor finally
>>took off his weight belt and put it across my legs, otherwise he had
>>to keep pulling me down to the bottom.
>
>That's air in your lungs causing that bouyancy. Solid tissue
>(whether it's bone, muscle, or fat) doesn't have anywhere near
>that amount of bouyancy. (It's also why when you get down below
>one atmosphere you lose bouyancy, as the air becomes more dense).
>[Unless you have football-sized sinuses, that is]

I call ! You're lungs don't change in volume. The air
pressure inside them is the same as the surrounding water. I don't
lose any bouancy at depth.


Next?

>
>He could also have given you a solid punch to the solar plexus to make
>you stay down, but I suppose that could have been rather more permanent.
>
>If you ever want to do it again, practice holding your breath with
>a relaxed expiration of your lungs.

--
dillon

"When the French are against it, you know we can't
be far wrong." - Adm. Bobbie Ray Inman

Dillon Pyron <dmpyronINVALID@austin.> wrote:

>>That's air in your lungs causing that bouyancy. Solid tissue
>>(whether it's bone, muscle, or fat) doesn't have anywhere near
>>that amount of bouyancy. (It's also why when you get down below
>>one atmosphere you lose bouyancy, as the air becomes more dense).
>>[Unless you have football-sized sinuses, that is]
>
>I call ! You're lungs don't change in volume. The air
>pressure inside them is the same as the surrounding water. I don't
>lose any bouancy at depth.

>Next?

As I point out, the density of the air increases. The pressure,
as you say, is the same as the surrounding water, which at 60ft/20m
is three atmospheres. Since, as you correctly point out, the volume
is the same, then the mass of the contained air is 3 times as much.
Bouyancy is thus lost. If your lungs were a glass fishingnet bouy
and the air contained didn't change pressure, then the bouyancy
wouldn't change at all.

Do you also have a problem with bouyancy changes from wetsuit
compression? It's the opposite side of the coin. [Volume changes,
mass stays the same].

Next?

--
Ken Tough

"Dillon Pyron" wrote

>>That's air in your lungs causing that bouyancy. Solid tissue
>>(whether it's bone, muscle, or fat) doesn't have anywhere near
>>that amount of bouyancy. (It's also why when you get down below
>>one atmosphere you lose bouyancy, as the air becomes more dense).
>>[Unless you have football-sized sinuses, that is]
>
> I call ! You're lungs don't change in volume. The air
> pressure inside them is the same as the surrounding water. I don't
> lose any bouancy at depth.

The volume of gas when your lungs are full, does not change, but the weight
of it does. Since water is, for practical purposes, not compressable, the
increase in the weight of the gas in the lungs should cause a slight shift
in buoyancy as it compresses. I suspect, however, that it would take a
great deal of compression to make a noticable difference.

I'm reasonably certain that statements that the inherent buoyancy of body
tissues is incorrect. There's sufficient evidence for me to conclude that,
all else being equal, it is the composition of the body that is the largest
factor for the buoyancy noted, ie the person that could not sit on the
bottom even with more weight than many can bring to the surface:
1. Fat floats. Bone and muscle do not. Easily proven by tossing the
various remains of a T-bone steak dinner in the water.
2. Women, who have an extra layer of fat, tend to be more buoyant than men
in similar physical condition.
3. At 18, when I took my Water Safety Instructor course, the hardest skill
for me, was floating. I had very little body fat and, even with a lung full
of air, I just barely managed to keep my face above water. At 57, I have a
lot more body fat and have as much trouble sinking as I once had floating.
I have to exhaust my lungs as completely as possible to sink at all and do
not ever sink flat to the bottom.

Lee

"Lee Bell" <leebell@ix.remove.netcom.com> wrote:

>"Dillon Pyron" wrote
>
>>>That's air in your lungs causing that bouyancy. Solid tissue
>>>(whether it's bone, muscle, or fat) doesn't have anywhere near
>>>that amount of bouyancy. (It's also why when you get down below
>>>one atmosphere you lose bouyancy, as the air becomes more dense).
>>>[Unless you have football-sized sinuses, that is]
>>
>> I call ! You're lungs don't change in volume. The air
>> pressure inside them is the same as the surrounding water. I don't
>> lose any bouancy at depth.
>
>The volume of gas when your lungs are full, does not change, but the weight
>of it does. Since water is, for practical purposes, not compressable, the
>increase in the weight of the gas in the lungs should cause a slight shift
>in buoyancy as it compresses. I suspect, however, that it would take a
>great deal of compression to make a noticable difference.
>
>I'm reasonably certain that statements that the inherent buoyancy of body
>tissues is incorrect. There's sufficient evidence for me to conclude that,
>all else being equal, it is the composition of the body that is the largest
>factor for the buoyancy noted, ie the person that could not sit on the
>bottom even with more weight than many can bring to the surface:
>1. Fat floats. Bone and muscle do not. Easily proven by tossing the
>various remains of a T-bone steak dinner in the water.
>2. Women, who have an extra layer of fat, tend to be more buoyant than men
>in similar physical condition.

Plus I was also pregnant and wearing a wet suit top. But even not
pregnant and not in a wet suit, I had a very hard time even doing a
surface dive, and could only do so by quickly flipping my legs
directly up over my body to drive myself down to the bottom. I've
never been able to swim down.

>3. At 18, when I took my Water Safety Instructor course, the hardest skill
>for me, was floating. I had very little body fat and, even with a lung full
>of air, I just barely managed to keep my face above water. At 57, I have a

We were taught that the balance point was the lungs. To do a quick
check on whether this procedure will work, have the person do a
jellyfish float with a full breath of air and observe - if any part of
the back sticks up out of the water then the person can float
motionless with their nose or mouth out of the water. Otherwise, they
will have to scull or expend some effort.

In order for an almost non floating person to float, you do the
following in this order - stopping when you can float.

a) fill the lungs
b) bend the knees and let the feet sink (keeping the thighs level with
the body)
c) tip the head back so that the whole top of the head down (or up) to
the eyes is submerged
d) move the arms UNDERWATER until they are extended over the head as
they would be at the top of an inverted breast stroke, or if you were
doing an upside-down butterfly.
e) stick the hands up out of the water (like rabbit ears)

>lot more body fat and have as much trouble sinking as I once had floating.
>I have to exhaust my lungs as completely as possible to sink at all and do
>not ever sink flat to the bottom.

>Lee
>

grandma Rosalie