Is it true (or an urban myth) that a swimmer would be sucked
under (presumably to drown) when a capital ship sinks?

On Tue, 22 Dec 2015 00:04:23 -0000 (UTC), "M. Stradbury"
wrote:

Is it true (or an urban myth) that a swimmer would be sucked
under (presumably to drown) when a capital ship sinks?

Myth

M. Stradbury wrote:
Is it true (or an urban myth) that a swimmer would be sucked
under (presumably to drown) when a capital ship sinks?

Like toilet bowl water swirls.

On Tue, 22 Dec 2015 00:04:23 -0000 (UTC), "M. Stradbury"
wrote:

Is it true (or an urban myth) that a swimmer would be sucked
under (presumably to drown) when a capital ship sinks?

I would think so. I was in a 6-man rubber raft that went over a
small falls and under water and though I wasn't tied to the raft, I
went under water too. How much more so with a big ship.

Something about traveling and being on my own made me fearless however
and I confidently waited, with my eyes open iirc, until I popped up
again a few seconds later. Without the raft.

This was the Dranze River in France, just east of Geneva, Switzerland.

On Mon, 21 Dec 2015 18:51:29 -0700, Tony Hwang
wrote:

M. Stradbury wrote:
Is it true (or an urban myth) that a swimmer would be sucked
under (presumably to drown) when a capital ship sinks?

Like toilet bowl water swirls.

I don't think the swirl is the part that matters. If you pour a
half-bucket of water in a toilet, it will drain without swirling. It's
the draining and emptying that matters.

Micky wrote:
On Tue, 22 Dec 2015 00:04:23 -0000 (UTC), "M. Stradbury"
wrote:

Is it true (or an urban myth) that a swimmer would be sucked
under (presumably to drown) when a capital ship sinks?

I would think so. I was in a 6-man rubber raft that went over a
small falls and under water and though I wasn't tied to the raft, I
went under water too. How much more so with a big ship.

Something about traveling and being on my own made me fearless however
and I confidently waited, with my eyes open iirc, until I popped up
again a few seconds later. Without the raft.

This was the Dranze River in France, just east of Geneva, Switzerland.

Basic fluid mechanics. You know that the swirl direction of opposite of
Southern hemisphere. CCW and CW. Rotating earth.

On Monday, December 21, 2015 at 8:03:04 PM UTC-6, Tony Hwang wrote:
Micky wrote:
On Tue, 22 Dec 2015 00:04:23 -0000 (UTC), "M. Stradbury"
wrote:

Is it true (or an urban myth) that a swimmer would be sucked
under (presumably to drown) when a capital ship sinks?

I would think so. I was in a 6-man rubber raft that went over a
small falls and under water and though I wasn't tied to the raft, I
went under water too. How much more so with a big ship.

Something about traveling and being on my own made me fearless however
and I confidently waited, with my eyes open iirc, until I popped up
again a few seconds later. Without the raft.

This was the Dranze River in France, just east of Geneva, Switzerland.

Basic fluid mechanics. You know that the swirl direction of opposite of
Southern hemisphere. CCW and CW. Rotating earth.

Hog wash about toilets...https://www.youtube.com/watch?v=ihv4f7VMeJw

bob_villain wrote:
On Monday, December 21, 2015 at 8:03:04 PM UTC-6, Tony Hwang wrote:
Micky wrote:
On Tue, 22 Dec 2015 00:04:23 -0000 (UTC), "M. Stradbury"
wrote:

Is it true (or an urban myth) that a swimmer would be sucked
under (presumably to drown) when a capital ship sinks?

I would think so. I was in a 6-man rubber raft that went over a
small falls and under water and though I wasn't tied to the raft, I
went under water too. How much more so with a big ship.

Something about traveling and being on my own made me fearless however
and I confidently waited, with my eyes open iirc, until I popped up
again a few seconds later. Without the raft.

This was the Dranze River in France, just east of Geneva, Switzerland.

Basic fluid mechanics. You know that the swirl direction of opposite of
Southern hemisphere. CCW and CW. Rotating earth.

Hog wash about toilets...https://www.youtube.com/watch?v=ihv4f7VMeJw

Didn't take physics in H.S. or college? Wondering.

On Mon, 21 Dec 2015 19:18:02 -0700, Tony Hwang
wrote:

bob_villain wrote:
On Monday, December 21, 2015 at 8:03:04 PM UTC-6, Tony Hwang wrote:
Micky wrote:
On Tue, 22 Dec 2015 00:04:23 -0000 (UTC), "M. Stradbury"
wrote:

Is it true (or an urban myth) that a swimmer would be sucked
under (presumably to drown) when a capital ship sinks?

I would think so. I was in a 6-man rubber raft that went over a
small falls and under water and though I wasn't tied to the raft, I
went under water too. How much more so with a big ship.

Something about traveling and being on my own made me fearless however
and I confidently waited, with my eyes open iirc, until I popped up
again a few seconds later. Without the raft.

This was the Dranze River in France, just east of Geneva, Switzerland.

Basic fluid mechanics. You know that the swirl direction of opposite of
Southern hemisphere. CCW and CW. Rotating earth.

Hog wash about toilets...https://www.youtube.com/watch?v=ihv4f7VMeJw

Didn't take physics in H.S. or college? Wondering.

I certainly took enough physics classes to know the direction of the
nozzles and shape of the bowl has more effect on the swirl than the
weak Coriolis effect

On Mon, 21 Dec 2015 19:02:56 -0700, Tony Hwang
wrote:

Micky wrote:
On Tue, 22 Dec 2015 00:04:23 -0000 (UTC), "M. Stradbury"
wrote:

Is it true (or an urban myth) that a swimmer would be sucked
under (presumably to drown) when a capital ship sinks?

In panic, someone might not hold his breath, and even more likely, he
might not take a big enough breath to be able to hold his breath for
long, but I would think if one does get a big breath and doesn't
panic, he should be able to hold it easily long enough to come to the
surface again.

Does it depend on how fat he is how fast he surfaces? Probably. So
if you anticipate being on a sinking ship, try to gain weight first.
(When my brother was in Viet Nam during the war, my mother wanted him
to gain weight to tide him over if he was taken prisoner. He didnt'
go on patrol and he wasn't a flier, so the odds were very slim he
would be taken prisoner, but other than that, I think she was right. )

I would think so. I was in a 6-man rubber raft that went over a
small falls and under water and though I wasn't tied to the raft, I
went under water too. How much more so with a big ship.

Something about traveling and being on my own made me fearless however
and I confidently waited, with my eyes open iirc, until I popped up
again a few seconds later. Without the raft.

This was the Dranze River in France, just east of Geneva, Switzerland.

Basic fluid mechanics.

You know that the swirl direction of opposite of
Southern hemisphere. CCW and CW. Rotating earth.

So I've heard.

Hmm. This post is not in reply to my reply to you where I took issue
with the importance of swirling. But I'll answer anyhow.

I'm not doubting that water in toilets swirls, or that water in eddies
swirls. I'm saying that swirling water has nothing to do with
sucking someone in behind a sinking ship.

In fact the water probably isn't swirling. The forces that make water
swirl, in a bathtub for example, are weak compared to the tremendous
amount of water that surrounds a large sinking ship. If the ship
were not sinking, there would be no swirling, and I don't think
sinking an inch every minute is enough to permit or cause swirling.

It's when the weight of the ship and the water it now contains is
greater than the weight of the water the whole ship displaces that
sinking quickly begins, and at that point there isn't time enough
before the ship has totally sunk for substantial swirling to begin.
Perhaps not any swirling at all. Note that it takes quite some time
to have it begin even in a bathtub.

The stage of sinking slowly can take hours, but when sinking quickly
begins, it takes no more than a minute, maybe two.

To beat this to death, I think the thousands of times people get to
watch water go down a sink drain overhwhelms their lack of experience
with sinking ships. However one can drop or throw rocks in a lake or
a river pool, off a pier for example, and see that there is no
swirling.

(One could even attach small balls that float to the rock, with some
weak "adhesive" that fails when wet, and time how long it takes the
balls to return the surface. Varying the depth of the water, or
the release time of the "glue", one could measure three data points
and extrapolate to a ship and a person, and a person with a life vest.

(Or maybe one doesn't need the rock for all of these experiements.
While the water falling into the opening would slow down resurfacing,
that water has filled in the hole within a measurable number of
seconds, and the real question is, What is the acceleration of a human
of given weight and size due to buoyancy, and how long would it take
to stop downward travel and cause upward travel, and what would the
total time be? All but the downward speed could be extrapolated just
from measurements made by releasing floating balls from an underwater
device.)

On Mon, 21 Dec 2015 21:46:01 -0500, wrote:

On Mon, 21 Dec 2015 19:18:02 -0700, Tony Hwang
wrote:

bob_villain wrote:
On Monday, December 21, 2015 at 8:03:04 PM UTC-6, Tony Hwang wrote:
Micky wrote:
On Tue, 22 Dec 2015 00:04:23 -0000 (UTC), "M. Stradbury"
wrote:

Is it true (or an urban myth) that a swimmer would be sucked
under (presumably to drown) when a capital ship sinks?

I would think so. I was in a 6-man rubber raft that went over a
small falls and under water and though I wasn't tied to the raft, I
went under water too. How much more so with a big ship.

Something about traveling and being on my own made me fearless however
and I confidently waited, with my eyes open iirc, until I popped up
again a few seconds later. Without the raft.

This was the Dranze River in France, just east of Geneva, Switzerland.

Basic fluid mechanics. You know that the swirl direction of opposite of
Southern hemisphere. CCW and CW. Rotating earth.

Hog wash about toilets...https://www.youtube.com/watch?v=ihv4f7VMeJw

Didn't take physics in H.S. or college? Wondering.

I certainly took enough physics classes to know the direction of the
nozzles and shape of the bowl has more effect on the swirl than the
weak Coriolis effect

The notion that water behaves differently in northern and southern
hemisphere basins is a nice little earner for smart operators living
on the equator. In reality, the direction in which the water goes down
the plughole is determined by several factors, such as the shape of
the basin, and the way the water is moving before the plug is removed,
etc. The position of the equator has no effect at all. There are
manufacturers in equatorial countries who make basins in 3 shapes, one
for north of the equator, one for south and one for right on the
equator. The aforementioned smart operators buy these basins and set
them up at appropriate places, and charge gullible tourists to watch
the water going down the 3 plugholes in what they imagine to be a
geographically-determined way.

Andrew Dickens, Bexhill-on-Sea UK

(The funniest explanation I've seen.)
http://www.theguardian.com/notesandq...-20326,00.html

Micky wrote:
On Mon, 21 Dec 2015 19:02:56 -0700, Tony Hwang
wrote:

Micky wrote:
On Tue, 22 Dec 2015 00:04:23 -0000 (UTC), "M. Stradbury"
wrote:

Is it true (or an urban myth) that a swimmer would be sucked
under (presumably to drown) when a capital ship sinks?

In panic, someone might not hold his breath, and even more likely, he
might not take a big enough breath to be able to hold his breath for
long, but I would think if one does get a big breath and doesn't
panic, he should be able to hold it easily long enough to come to the
surface again.

Does it depend on how fat he is how fast he surfaces? Probably. So
if you anticipate being on a sinking ship, try to gain weight first.
(When my brother was in Viet Nam during the war, my mother wanted him
to gain weight to tide him over if he was taken prisoner. He didnt'
go on patrol and he wasn't a flier, so the odds were very slim he
would be taken prisoner, but other than that, I think she was right. )

I would think so. I was in a 6-man rubber raft that went over a
small falls and under water and though I wasn't tied to the raft, I
went under water too. How much more so with a big ship.

Something about traveling and being on my own made me fearless however
and I confidently waited, with my eyes open iirc, until I popped up
again a few seconds later. Without the raft.

This was the Dranze River in France, just east of Geneva, Switzerland.

Basic fluid mechanics.

You know that the swirl direction of opposite of
Southern hemisphere. CCW and CW. Rotating earth.

So I've heard.

Hmm. This post is not in reply to my reply to you where I took issue
with the importance of swirling. But I'll answer anyhow.

I'm not doubting that water in toilets swirls, or that water in eddies
swirls. I'm saying that swirling water has nothing to do with
sucking someone in behind a sinking ship.

In fact the water probably isn't swirling. The forces that make water
swirl, in a bathtub for example, are weak compared to the tremendous
amount of water that surrounds a large sinking ship. If the ship
were not sinking, there would be no swirling, and I don't think
sinking an inch every minute is enough to permit or cause swirling.
m
It's when the weight of the ship and the water it now contains is
greater than the weight of the water the whole ship displaces that
sinking quickly begins, and at that point there isn't time enough
before the ship has totally sunk for substantial swirling to begin.
Perhaps not any swirling at all. Note that it takes quite some time
to have it begin even in a bathtub.

The stage of sinking slowly can take hours, but when sinking quickly
begins, it takes no more than a minute, maybe two.

To beat this to death, I think the thousands of times people get to
watch water go down a sink drain overhwhelms their lack of experience
with sinking ships. However one can drop or throw rocks in a lake or
a river pool, off a pier for example, and see that there is no
swirling.

(One could even attach small balls that float to the rock, with some
weak "adhesive" that fails when wet, and time how long it takes the
balls to return the surface. Varying the depth of the water, or
the release time of the "glue", one could measure three data points
and extrapolate to a ship and a person, and a person with a life vest.

(Or maybe one doesn't need the rock for all of these experiements.
While the water falling into the opening would slow down resurfacing,
that water has filled in the hole within a measurable number of
seconds, and the real question is, What is the acceleration of a human
of given weight and size due to buoyancy, and how long would it take
to stop downward travel and cause upward travel, and what would the
total time be? All but the downward speed could be extrapolated just
from measurements made by releasing floating balls from an underwater
device.)

Hey, couple months ago whale watching boat rolled and sank hit by a big
wave West of Vancouver Island, few died and some survived. A couple
survived is from Calgary here. They both said they got sucked under and
then surfaced. My 2nd uncle is life time Navy man, Captain(ret), ROKN.
He said same thing.

On 22/12/2015 11:04 AM, M. Stradbury wrote:
Is it true (or an urban myth) that a swimmer would be sucked
under (presumably to drown) when a capital ship sinks?


Mythbusters tried it, and concluded that there was no significant
sucking sown.

https://www.youtube.com/watch?v=rvU_dkKdZ0U

Sylvia.

On Mon, 21 Dec 2015 20:47:56 -0700, Tony Hwang
wrote:

Micky wrote:
On Mon, 21 Dec 2015 19:02:56 -0700, Tony Hwang
wrote:

Micky wrote:
On Tue, 22 Dec 2015 00:04:23 -0000 (UTC), "M. Stradbury"
wrote:

Is it true (or an urban myth) that a swimmer would be sucked
under (presumably to drown) when a capital ship sinks?

In panic, someone might not hold his breath, and even more likely, he
might not take a big enough breath to be able to hold his breath for
long, but I would think if one does get a big breath and doesn't
panic, he should be able to hold it easily long enough to come to the
surface again.

Does it depend on how fat he is how fast he surfaces? Probably. So
if you anticipate being on a sinking ship, try to gain weight first.
(When my brother was in Viet Nam during the war, my mother wanted him
to gain weight to tide him over if he was taken prisoner. He didnt'
go on patrol and he wasn't a flier, so the odds were very slim he
would be taken prisoner, but other than that, I think she was right. )

I would think so. I was in a 6-man rubber raft that went over a
small falls and under water and though I wasn't tied to the raft, I
went under water too. How much more so with a big ship.

Something about traveling and being on my own made me fearless however
and I confidently waited, with my eyes open iirc, until I popped up
again a few seconds later. Without the raft.

This was the Dranze River in France, just east of Geneva, Switzerland.

Basic fluid mechanics.

You know that the swirl direction of opposite of
Southern hemisphere. CCW and CW. Rotating earth.

So I've heard.

Hmm. This post is not in reply to my reply to you where I took issue
with the importance of swirling. But I'll answer anyhow.

I'm not doubting that water in toilets swirls, or that water in eddies
swirls. I'm saying that swirling water has nothing to do with
sucking someone in behind a sinking ship.

In fact the water probably isn't swirling. The forces that make water
swirl, in a bathtub for example, are weak compared to the tremendous
amount of water that surrounds a large sinking ship. If the ship
were not sinking, there would be no swirling, and I don't think
sinking an inch every minute is enough to permit or cause swirling.
m
It's when the weight of the ship and the water it now contains is
greater than the weight of the water the whole ship displaces that
sinking quickly begins, and at that point there isn't time enough
before the ship has totally sunk for substantial swirling to begin.
Perhaps not any swirling at all. Note that it takes quite some time
to have it begin even in a bathtub.

The stage of sinking slowly can take hours, but when sinking quickly
begins, it takes no more than a minute, maybe two.

To beat this to death, I think the thousands of times people get to
watch water go down a sink drain overhwhelms their lack of experience
with sinking ships. However one can drop or throw rocks in a lake or
a river pool, off a pier for example, and see that there is no
swirling.

(One could even attach small balls that float to the rock, with some
weak "adhesive" that fails when wet, and time how long it takes the
balls to return the surface. Varying the depth of the water, or
the release time of the "glue", one could measure three data points
and extrapolate to a ship and a person, and a person with a life vest.

(Or maybe one doesn't need the rock for all of these experiements.
While the water falling into the opening would slow down resurfacing,
that water has filled in the hole within a measurable number of
seconds, and the real question is, What is the acceleration of a human
of given weight and size due to buoyancy, and how long would it take
to stop downward travel and cause upward travel, and what would the
total time be? All but the downward speed could be extrapolated just
from measurements made by releasing floating balls from an underwater
device.)

Hey, couple months ago whale watching boat rolled and sank hit by a big
wave West of Vancouver Island, few died and some survived. A couple

I heard abou tthat.

survived is from Calgary here. They both said they got sucked under and
then surfaced. My 2nd uncle is life time Navy man, Captain(ret), ROKN.
He said same thing.

I didn't hear about that. Good to know. Should make OP happy to
know too.

Just remember to pretend you're in the doctor's office, suck in a big
breath and hold it.

Sylvia Else wrote:
On 22/12/2015 11:04 AM, M. Stradbury wrote:
Is it true (or an urban myth) that a swimmer would be sucked
under (presumably to drown) when a capital ship sinks?


Mythbusters tried it, and concluded that there was no significant
sucking sown.

https://www.youtube.com/watch?v=rvU_dkKdZ0U

Sylvia.

So when ship is abandoned, crews jump off the ship, they hang around the
sinking ship, right? They always swim away from the ship as much as
they can. Ask any sailors.

On 12/21/2015 07:51 PM, Tony Hwang wrote:
M. Stradbury wrote:
Is it true (or an urban myth) that a swimmer would be sucked
under (presumably to drown) when a capital ship sinks?

Like toilet bowl water swirls.

I think there was a TV show where a kid called a lot of people in places
like Australia, to ask them which way the water swirls when they flush.

--
4 days until the winter celebration (Friday December 25, 2015 12:00:00
AM for 1 day).

"We could believe in God if he shortened the road for the lame, led the
blind or fed the starving." [Lemuel K. Washburn, _Is The Bible Worth
Reading And Other Essays_]

On Mon, 21 Dec 2015 18:51:29 -0700, Tony Hwang wrote:

Like toilet bowl water swirls.

A toilet bowl is too small to show the Coriolis effect, but a pool isn't
according to Sandlin and Muller.

http://mashable.com/2015/06/04/water.../#vRjaqfm0bSqs
"Derek Muller and Destin Sandlin, the minds behind the Veritasium and
Smarter Every Day YouTube channels, respectively, do show that water
(and even hurricanes or cycloness) preferentially spins counter-clockwise
in the north and clockwise in the south, you just might not be able to
see it with your toilet water."

On Mon, 21 Dec 2015 22:18:50 -0500, Micky wrote:

The notion that water behaves differently in northern and southern
hemisphere basins is a nice little earner for smart operators living
on the equator

A toilet bowl is too small to show the Coriolis effect, but a pool isn't
according to Sandlin and Muller.

http://mashable.com/2015/06/04/water.../#vRjaqfm0bSqs
"Derek Muller and Destin Sandlin, the minds behind the Veritasium and
Smarter Every Day YouTube channels, respectively, do show that water
(and even hurricanes or cycloness) preferentially spins counter-clockwise
in the north and clockwise in the south, you just might not be able to
see it with your toilet water."

On Tue, 22 Dec 2015 14:51:47 +1100, Sylvia Else wrote:

Mythbusters tried it, and concluded that there was no significant
sucking sown.

https://www.youtube.com/watch?v=rvU_dkKdZ0U

Sylvia.

Nice find!

Will a Sinking Ship Suck You Down with It? | MythBusters
https://www.youtube.com/watch?v=rvU_dkKdZ0U

Theory 1:
Air mixes with water makes the water less dense, hence
sucking you down.
Theory 2:
Cavities in ship causes water to rush into the ship, hence
sucking you down.
Theory 3:
Ship falling down creates a vortex above it, hence
sucking you down.

On 22/12/2015 3:06 PM, Tony Hwang wrote:
Sylvia Else wrote:
On 22/12/2015 11:04 AM, M. Stradbury wrote:
Is it true (or an urban myth) that a swimmer would be sucked
under (presumably to drown) when a capital ship sinks?


Mythbusters tried it, and concluded that there was no significant
sucking sown.

https://www.youtube.com/watch?v=rvU_dkKdZ0U

Sylvia.

So when ship is abandoned, crews jump off the ship, they hang around the
sinking ship, right? They always swim away from the ship as much as
they can. Ask any sailors.

That's rather circular.

There is a wide spread belief that one can get sucked down, and there's
no reason to think sailors have any better knowledge of this than anyone
else - it's hardly something most will ever experience - consequently
one would expect them to swim away.

Anyway, sucking people down is not the only possible hazard represented
by a sinking ship.

Sylvia.

Sylvia Else wrote:
On 22/12/2015 3:06 PM, Tony Hwang wrote:
Sylvia Else wrote:
On 22/12/2015 11:04 AM, M. Stradbury wrote:
Is it true (or an urban myth) that a swimmer would be sucked
under (presumably to drown) when a capital ship sinks?


Mythbusters tried it, and concluded that there was no significant
sucking sown.

https://www.youtube.com/watch?v=rvU_dkKdZ0U

Sylvia.

So when ship is abandoned, crews jump off the ship, they hang around the
sinking ship, right? They always swim away from the ship as much as
they can. Ask any sailors.

That's rather circular.

There is a wide spread belief that one can get sucked down, and there's
no reason to think sailors have any better knowledge of this than anyone
else - it's hardly something most will ever experience - consequently
one would expect them to swim away.

Anyway, sucking people down is not the only possible hazard represented
by a sinking ship.

Sylvia.

Do you have any maritime experience? Worked on any kind of ocean going
vessel(s)? Possess any knowledge gained from real life experience?

Back then, the reason to get away from the sinking ships was not the
suction but the boilers exploding.

On Mon, 21 Dec 2015 21:06:35 -0700, Tony Hwang
wrote:

Sylvia Else wrote:
On 22/12/2015 11:04 AM, M. Stradbury wrote:
Is it true (or an urban myth) that a swimmer would be sucked
under (presumably to drown) when a capital ship sinks?


Mythbusters tried it, and concluded that there was no significant
sucking sown.

https://www.youtube.com/watch?v=rvU_dkKdZ0U

Sylvia.

So when ship is abandoned, crews jump off the ship, they hang around the
sinking ship, right? They always swim away from the ship as much as
they can. Ask any sailors.

I was a sailor (blue water USCG) and there are lots of reasons to get
away. For one, you really don't want to get caught in the oil slick.
That is plenty of reason, right there.
The oil can be on fire or catch fire.
On a war ship, there might be some ordinance that will go off.
If you are close you might also get snagged in the rigging. That will
drag you down for sure.

On 22/12/2015 4:19 PM, Tony Hwang wrote:

Do you have any maritime experience? Worked on any kind of ocean
going vessel(s)? Possess any knowledge gained from real life
experience?

Experience of ships? No. How would any of that help in deciding whether
the vessel would suck me down if it sank?

Or do you think there's some sort of mechanism that allows enlightenment
by osmosis?

Sylvia.

On Monday, December 21, 2015 at 9:13:33 PM UTC-6, Micky wrote:
On Mon, 21 Dec 2015 19:02:56 -0700, Tony Hwang
wrote:

Micky wrote:
On Tue, 22 Dec 2015 00:04:23 -0000 (UTC), "M. Stradbury"
wrote:

Is it true (or an urban myth) that a swimmer would be sucked
under (presumably to drown) when a capital ship sinks?

In panic, someone might not hold his breath, and even more likely, he
might not take a big enough breath to be able to hold his breath for
long, but I would think if one does get a big breath and doesn't
panic, he should be able to hold it easily long enough to come to the
surface again.

Does it depend on how fat he is how fast he surfaces? Probably. So
if you anticipate being on a sinking ship, try to gain weight first.
(When my brother was in Viet Nam during the war, my mother wanted him
to gain weight to tide him over if he was taken prisoner. He didnt'
go on patrol and he wasn't a flier, so the odds were very slim he
would be taken prisoner, but other than that, I think she was right. )

I would think so. I was in a 6-man rubber raft that went over a
small falls and under water and though I wasn't tied to the raft, I
went under water too. How much more so with a big ship.

Something about traveling and being on my own made me fearless however
and I confidently waited, with my eyes open iirc, until I popped up
again a few seconds later. Without the raft.

This was the Dranze River in France, just east of Geneva, Switzerland.

Basic fluid mechanics.

You know that the swirl direction of opposite of
Southern hemisphere. CCW and CW. Rotating earth.

So I've heard.

Hmm. This post is not in reply to my reply to you where I took issue
with the importance of swirling. But I'll answer anyhow.

I'm not doubting that water in toilets swirls, or that water in eddies
swirls. I'm saying that swirling water has nothing to do with
sucking someone in behind a sinking ship.

In fact the water probably isn't swirling. The forces that make water
swirl, in a bathtub for example, are weak compared to the tremendous
amount of water that surrounds a large sinking ship. If the ship
were not sinking, there would be no swirling, and I don't think
sinking an inch every minute is enough to permit or cause swirling.

It's when the weight of the ship and the water it now contains is
greater than the weight of the water the whole ship displaces that
sinking quickly begins, and at that point there isn't time enough
before the ship has totally sunk for substantial swirling to begin.
Perhaps not any swirling at all. Note that it takes quite some time
to have it begin even in a bathtub.

The stage of sinking slowly can take hours, but when sinking quickly
begins, it takes no more than a minute, maybe two.

To beat this to death, I think the thousands of times people get to
watch water go down a sink drain overhwhelms their lack of experience
with sinking ships. However one can drop or throw rocks in a lake or
a river pool, off a pier for example, and see that there is no
swirling.

(One could even attach small balls that float to the rock, with some
weak "adhesive" that fails when wet, and time how long it takes the
balls to return the surface. Varying the depth of the water, or
the release time of the "glue", one could measure three data points
and extrapolate to a ship and a person, and a person with a life vest.

(Or maybe one doesn't need the rock for all of these experiements.
While the water falling into the opening would slow down resurfacing,
that water has filled in the hole within a measurable number of
seconds, and the real question is, What is the acceleration of a human
of given weight and size due to buoyancy, and how long would it take
to stop downward travel and cause upward travel, and what would the
total time be? All but the downward speed could be extrapolated just
from measurements made by releasing floating balls from an underwater
device.)

How many tours did your brother do in Nam? My oldest brother did two but none of the rest of us brothers wound up in the military during the Vietnam War even though two more off us were of draft age. (”�'_')”� BAM ”“('_'”“)

[8~{} Uncle Army Monster

On Mon, 21 Dec 2015 23:59:04 -0800 (PST), Uncle Monster
wrote:


(Or maybe one doesn't need the rock for all of these experiements.
While the water falling into the opening would slow down resurfacing,
that water has filled in the hole within a measurable number of
seconds, and the real question is, What is the acceleration of a human
of given weight and size due to buoyancy, and how long would it take
to stop downward travel and cause upward travel, and what would the
total time be? All but the downward speed could be extrapolated just
from measurements made by releasing floating balls from an underwater
device.)

How many tours did your brother do in Nam?

Just one year. At Can Tho for about 4 months and Cu Chi for 8.

He's a doctor, and might have been drafted as an intern, but the army
encouraged people like him to enlist and then they would let you
finish your residency before you had to serve. That way the army got
a specialist instead of a GP. My brother is a radiologist (but
lately I've learned how much medicine he knows about other areas,
which isnt' surprising since he went to med school, but even things
which are new since school.) It was called the Berry Plan.

Then he did a year at Ft. Devins, near Boston.

My mother kept a map of Viet Nam and watched the news for stories
about the areas where he was. I just waited.

My oldest brother did two

Something to be proud of.

but none of the rest of us brothers wound up in the military during the Vietnam War even though two more off us were of draft age. (?'_')? BAM ?('_'?)

How did that happen.

My lottery number was 17, but I had two shoulders that repeatedly
dislocated. They both got somewhat better after a summer's hard work,
but then I got 2000 volts from a TV and dislocated one of them, fell
back and dislocated the other. The first side came out 10 times that
month and I finally had surgery. I can't sleep with my arm above my
head anymore, but otherwise it's 36 years and doing fine.

[8~{} Uncle Army Monster

Dne 22/12/2015 v 01:04 M. Stradbury napsal(a):
Is it true (or an urban myth) that a swimmer would be sucked
under (presumably to drown) when a capital ship sinks?

I suppose there are many eye witnesses.

My not confirmed idea is,

that for very most time
is sinking too slow to be dangerous in this way.

But in final stage,
the one ship end is often submersed
and the ship is sliding down fast,
or the ships turns upside down,
or horizontally positioned ship accelerates
sinking toward the bottom.

In such scenario the motion is fast,
causing vertical streams and vertigos.

--
Poutnik ( the Czech word for a wanderer )

Knowledge makes great men humble, but small men arrogant.

Dne 22/12/2015 v 02:56 Micky napsal(a):
On Tue, 22 Dec 2015 00:04:23 -0000 (UTC), "M. Stradbury"
wrote:

Is it true (or an urban myth) that a swimmer would be sucked
under (presumably to drown) when a capital ship sinks?

I would think so. I was in a 6-man rubber raft that went over a
small falls and under water and though I wasn't tied to the raft, I
went under water too. How much more so with a big ship.

But it could be because of your motion dynamics,
as you inertially continue water under,
until your buoyancy gradually reverted your velocity.


--
Poutnik ( the Czech word for a wanderer )

Knowledge makes great men humble, but small men arrogant.

Dne 22/12/2015 v 04:51 Sylvia Else napsal(a):
On 22/12/2015 11:04 AM, M. Stradbury wrote:
Is it true (or an urban myth) that a swimmer would be sucked
under (presumably to drown) when a capital ship sinks?


Mythbusters tried it, and concluded that there was no significant
sucking sown.

I have often the impression their experiments are designed
in the first place rather for the effect,
than to really investigate the nature of phenomena.

E.g. I watched their investigation of economic effect
of frequent switching on/off
the incandescent, fluorescent and LED lights.

They were over focused to refute the obvious nonsense
the light at switching consume more power
than saved by being off, and were successful there.

OTOH, experiment part about saving power
versus shortening device life was very poorly designed
and result had no statistical value.

--
Poutnik ( the Czech word for a wanderer )

Knowledge makes great men humble, but small men arrogant.

On Tue, 22 Dec 2015 10:18:34 +0100, Poutnik
wrote:

Dne 22/12/2015 v 02:56 Micky napsal(a):
On Tue, 22 Dec 2015 00:04:23 -0000 (UTC), "M. Stradbury"
wrote:

Is it true (or an urban myth) that a swimmer would be sucked
under (presumably to drown) when a capital ship sinks?

I would think so. I was in a 6-man rubber raft that went over a
small falls and under water and though I wasn't tied to the raft, I
went under water too. How much more so with a big ship.

But it could be because of your motion dynamics,
as you inertially continue water under,
until your buoyancy gradually reverted your velocity.

True. I'm no longer convinced. (Even though I doubt mythbusters on
general principles). If one were right by the ship when it went
quickly down, one would fall into the hole it left, but the water it
pushed aside would be crashing back right after the ship passed also.
How deep the person would go is a question.

I think if you were standing on the deck, whether the deck was
horizontal or leaning, you could drop as fast as the ship did. Why
not? Until there was enough water surrouding you for buoyancy to
matter.

But if you were 3 inches from the ship, already floating in the water,
would you fall over like in a waterfall? I think so, but like I say,
you'd be competing with the water to see who and what dropped first.

One could experiement with little floating balls and big rocks dropped
close to them, or better yet, held close to them at surface level and
then released. A method for determining how deep they go would be
needed.

Anyhow my point originally was no swirling. I coudl have kept silent
on other stuff.

Dne 22/12/2015 v 08:58 Sylvia Else napsal(a):
On 22/12/2015 4:19 PM, Tony Hwang wrote:

Do you have any maritime experience? Worked on any kind of ocean
going vessel(s)? Possess any knowledge gained from real life
experience?

Experience of ships? No. How would any of that help in deciding whether
the vessel would suck me down if it sank?

Or do you think there's some sort of mechanism that allows enlightenment
by osmosis?


Nautical society has advantage of collective experience
of huge number of people, surviving the ship sinking.

Even if I had been Nobel laureate for physics,
sailors would know more about surviving on sea than me.

If personalizing,
Sea has already laughed to many theoretical thoughts.

--
Poutnik ( the Czech word for a wanderer )

Knowledge makes great men humble, but small men arrogant.

Dne 22/12/2015 v 05:36 M. Stradbury napsal(a):

Theory 1:
Air mixes with water makes the water less dense, hence
sucking you down.

I have seen a video where a boat was in a lab sinked by this way,

in document about the Bermuda triangle,
following the hypothesis
about sudden huge gas release
from the sea bad or underwater vulcanos.

Sinking a swimmer with density close to water
is much easier than sinking a boat.

--
Poutnik ( the Czech word for a wanderer )

Knowledge makes great men humble, but small men arrogant.

Dne 22/12/2015 v 07:06 O napsal(a):
Back then, the reason to get away from the sinking ships was not the
suction but the boilers exploding.

I agree it is the best to get far from a wreck
independently on if whirl sucking is a danger or not.

--
Poutnik ( the Czech word for a wanderer )

Knowledge makes great men humble, but small men arrogant.

On Tue, 22 Dec 2015 11:13:47 +0100, Poutnik
wrote:


Dne 22/12/2015 v 05:36 M. Stradbury napsal(a):

Theory 1:
Air mixes with water makes the water less dense, hence
sucking you down.

I have seen a video where a boat was in a lab sinked by this way,

I knew a guy who drowned in club soda.

I think there was a lot of scotch, too.

On 22/12/2015 9:06 PM, Poutnik wrote:
Dne 22/12/2015 v 08:58 Sylvia Else napsal(a):
On 22/12/2015 4:19 PM, Tony Hwang wrote:

Do you have any maritime experience? Worked on any kind of ocean
going vessel(s)? Possess any knowledge gained from real life
experience?

Experience of ships? No. How would any of that help in deciding whether
the vessel would suck me down if it sank?

Or do you think there's some sort of mechanism that allows enlightenment
by osmosis?


Nautical society has advantage of collective experience
of huge number of people, surviving the ship sinking.

Even if I had been Nobel laureate for physics,
sailors would know more about surviving on sea than me.

For most things, perhaps. But how many sailors have experience of a
sinking, much less such experience from the the immediate vicinity of
the ship. Those who got sucked down, if any, won't be around to tell the
tale. Those who didn't get sucked down, and survived, would be
counter-examples.

Sylvia.

Dne 22/12/2015 v 12:13 Sylvia Else napsal(a):
On 22/12/2015 9:06 PM, Poutnik wrote:


For most things, perhaps. But how many sailors have experience of a
sinking, much less such experience from the the immediate vicinity of
the ship. Those who got sucked down, if any, won't be around to tell the
tale. Those who didn't get sucked down, and survived, would be
counter-examples.

I do not say current sailors, but history
of survival records and withnesses.

There are 2 other options.

Those surviving seeing others being sucked down,
Those being sucked down not enough to die.

--
Poutnik ( the Czech word for a wanderer )

Knowledge makes great men humble, but small men arrogant.

Dne 22/12/2015 v 04:51 Sylvia Else napsal(a):
On 22/12/2015 11:04 AM, M. Stradbury wrote:
Is it true (or an urban myth) that a swimmer would be sucked
under (presumably to drown) when a capital ship sinks?


Mythbusters tried it, and concluded that there was no significant
sucking sown.

https://www.youtube.com/watch?v=rvU_dkKdZ0U

But the did not make any attempt
to maintain geometrical similarity.

IF a sailor size was 1/4 of a ship size,
he would not be sucked either.

I am not sure, if the viscosity has to be scaled
as well for that matter, but I guess it has.

As I mentioned in my other post
the Mythbusters do not care much
about reliability of their experiments and interpretations.

--
Poutnik ( the Czech word for a wanderer )

Knowledge makes great men humble, but small men arrogant.

"Sylvia Else" wrote in message
...
On 22/12/2015 11:04 AM, M. Stradbury wrote:
Is it true (or an urban myth) that a swimmer would be sucked
under (presumably to drown) when a capital ship sinks?


Mythbusters tried it, and concluded that there was no significant sucking
sown.

https://www.youtube.com/watch?v=rvU_dkKdZ0U

Sylvia.

mythbusters is a crock.

Per M. Stradbury:
Is it true (or an urban myth) that a swimmer would be sucked
under (presumably to drown) when a capital ship sinks?

Dunno what a capital ship is but am guessing it's big.

I saw an interview clip in which Lord Louis Mountbatten told of
surviving his destroyer's sinking - along with a senior NCO who said at
the time something like "Well sir, the scum always rises to the surface"
so I am guessing that both were in the water when the ship went down
under them.

--
Pete Cresswell

On Tue, 22 Dec 2015 08:53:14 -0500, (PeteCresswell) wrote:

Dunno what a capital ship is but am guessing it's big.

My bad for not defining it, but you, sir, are correct, although
in looking it up, I realized I was not correct:

https://en.wikipedia.org/wiki/Capital_ship