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Warren
January 17th, 2007, 04:36 PM
I'm back at school now and it feels so much better swimming at my schools pool than at my local Y becasuse my school pool has a 13 feet deep end. the Y is shallow, its 3 feet on one end.

Deep water is so much better than shallow water.

scyfreestyler
January 17th, 2007, 05:17 PM
Hmm? 3 feet is pretty shallow but I do sometimes enjoy swimming in the shallow end of our teams pool..4 feet. To me it seems to be faster than the deep end but it might just be an illusion created by being closer to the lines on the pool bottom.

rtodd
January 17th, 2007, 05:22 PM
my pool is 3' at one end and 7 at the other. The deep end is noticably faster.

poolraat
January 17th, 2007, 05:29 PM
My pool is 3.5 at one end and 6 at the other. I sometimes have problems with my backstroke turn on the shallow end. I'll get too close to the bottom as I SDK away, my heels and butt keep hitting bottom and I can't get away. End up doing a double arm pull and flutter kick to get back to the surface.
Anyone else experienced this?

scyfreestyler
January 17th, 2007, 05:34 PM
I don't backstroke due to my shoulders but 3.5 feet is kinda shallow and I can understand how you would have such a problem.

blainesapprentice
January 17th, 2007, 07:35 PM
Deep water is faster...at least according to my assistant coach...

he was talking to us the other day about how when you do dolphin kick off the walls/starts you create these things like little eddy's in the water that project from your kicks radius upward and downward...the farther you project these eddy's (aka the more powerful and whip like your dolphin kick is) the faster you will move...however in the shallow water, those swirls can only go as far as the bottom of the pool--which is obviously very close...so you do not get as much momentum and speed from your efforts....

idk how true that is...but my deep end turns have always felt more powerful and efficient.

I've also heard that you want to be an equal distance between the surface and the bottom (esp. in the shallow end) for optimal use of the water?

Morgan

rtodd
January 17th, 2007, 07:44 PM
I think you are right about having SDK reflecting back up at you.

Perhaps more importantly is the increased shear created from your body moving over the narrower column of water in the shallow end. Remember water has viscosity (the measured resistance of a fluid to flow). I'd have to crack open a fluid mechanics book from college to go into it further. Without having to open it though, I know for a fact that the deeper water is faster.

It is easier to "hang out" in the shallow end between repeats, but I wish it was deeper. Flip turns in 3 feet of water can be hazardous.

poolraat
January 17th, 2007, 07:53 PM
...he was talking to us the other day about how when you do dolphin kick off the walls/starts you create these things like little eddy's in the water that project from your kicks radius upward and downward...the farther you project these eddy's (aka the more powerful and whip like your dolphin kick is) the faster you will move...however in the shallow water, those swirls can only go as far as the bottom of the pool--which is obviously very close...so you do not get as much momentum and speed from your efforts....

According to our age group club coach, that's why they want their swimmers to dolphin on their side rather than flat on the back or belly. The only problem with this would be the possibility of rotating past vertical and getting DQ'd.

scyfreestyler
January 17th, 2007, 08:13 PM
I think you are right about having SDK reflecting back up at you.

Perhaps more importantly is the increased shear created from your body moving over the narrower column of water in the shallow end. Remember water has viscosity (the measured resistance of a fluid to flow). I'd have to crack open a fluid mechanics book from college to go into it further. Without having to open it though, I know for a fact that the deeper water is faster.

It is easier to "hang out" in the shallow end between repeats, but I wish it was deeper. Flip turns in 3 feet of water can be hazardous.

Perhaps I am misunderstanding the principle but I fail to see what the depth of the water has to do with the viscosity of the water near the surface where we swim. :dunno:

LindsayNB
January 17th, 2007, 08:36 PM
My guess is that the main affect of a deeper pool is that the water will be less turbulent. Water pushed downward by your kicks for example will largely head off into the depths, being damped out by viscousity along the way, while in a shallow pool it will be bouncing off the bottom of the pool and creating currents that you have to swim through on your return trip. Unless you have a large scale current flowing in your direction of travel, you will usually swim fastest in still water. In a way all that water down in the depths is acting like an anti-wave lane line but in a vertical plane. In a really shallow pool, after you turn it will be difficult to get under the water that you were dragging toward the wall before the turn, and especially to get under that moving water and still attain a full range of kicking movement without hitting bottom.

swim4me
January 17th, 2007, 08:44 PM
It is easier to "hang out" in the shallow end between repeats, but I wish it was deeper. Flip turns in 3 feet of water can be hazardous.

I have heard that deep pools are faster as well. Intersting discussions on the reason for it. My pool is 7 feet deep where I swim by one of the ends of the pool. (50 meters long, 7 feet deep on each end and 4 ft deep in the middle. It is set up for 25 yards right now, which is the width of the pool). It is great for the SDK's, not having to worry about how deep I go. It is a drag, though, having to hang on to the gutter while trying to breathe between sets.

Allen Stark
January 17th, 2007, 08:57 PM
Ben Franklin proved that deeper water was faster than shallow by observing barges in a canal. I believe Lindsay's explanation is accurate.

rtodd
January 18th, 2007, 11:30 AM
Perhaps I am misunderstanding the principle but I fail to see what the depth of the water has to do with the viscosity of the water near the surface where we swim

I only mention that water is a fluid which has viscosity or the resistance to flow. That is a constant, but it is this property that causes a resistant force which is inversely proportional to the depth of the water. For a swimmer in deep water, the depth of the water is not the dominant resistant force. The dominant resistance is the drag created by our bodies in the water. When the depth of the water is significantly reduced the shear force is increased as the depth is decreased due to an increased change in angular velocity and this added component in the total equation becomes significant enough to be felt and it slows us down.

My feeling is that at depth of 3 feet, it is significant and falls out of the resistance equation at 7 feet. That is a guess. I'm sure this research has been exhaustive and well defined.

poolraat
January 18th, 2007, 11:36 AM
I only mention that water is a fluid which has viscosity or the resistance to flow. That is a constant, but it is this property that causes a resistant force which is inversely proportional to the depth of the water. For a swimmer in deep water, the depth of the water is not the dominant resistant force. The dominant resistance is the drag created by our bodies in the water. When the depth of the water is significantly reduced the shear force is increased as the depth is decreased due to an increased change in angular velocity and this added component in the total equation becomes significant enough to be felt and it slows us down.

My feeling is that at depth of 3 feet, it is significant and falls out of the resistance equation at 7 feet. That is a guess. I'm sure this research has been exhaustive and well defined.


Good explanation. You must have pulled out the fluids text and read up.
It's been so long I'm not even sure where mine is any more. I probably couldn't make sense out of what I was reading anyway.:dunno:

I think that's why some coaches want their swimmers dolphining on their sides. Unless one is in the outside lanes, it makes the walls the bottom thereby increasing the effective depth of the pool.

rtodd
January 18th, 2007, 11:54 AM
I also think what Lindsay says is true about having to get underneath your own water at the turns. Can't be done in a 3' pool. this is probably more significant than anything.

scyfreestyler
January 18th, 2007, 12:02 PM
I also think what Lindsay says is true about having to get underneath your own water at the turns. Can't be done in a 3' pool. this is probably more significant than anything.

I can agree with this for certain...especially when you are side by side sharing a lane with another swimmer.

Redbird Alum
January 19th, 2007, 01:20 AM
I also think what Lindsay says is true about having to get underneath your own water at the turns. Can't be done in a 3' pool. this is probably more significant than anything.

This leads to an interesting question... since many of us are stuck with our 3 - 3.5 depths at one end and have to deal with it...

Is it more efficient to try to center your push-off within the incoming water stream, or try to angle off to a side (which I would think would throw off your mechanics as you adjust to the uneven flow)?

Michael Heather
January 19th, 2007, 01:45 AM
How about discussing the turbulence and volume of water?

There is no stream of water following you into a wall to turn, just the turbulence created in the approach. If your streamline is nice and tight and you push off square to the wall, you will not notice very much past 3 feet from the wall where your (kicking) feet last were.

And quit being such babies about 3 feet of water in which to turn! In college, I regularly swam in park pools during Summer practice that were 24 inches or less deep at the wall in the shallow end. THAT was hard to turn on. But my fingernails were always nicely trimmed.

Deep water is faster? Probably. But consider this. In 1974, John Trembly set an American record of 20.066 for the 50 Freestyle in NCAA Championships held in Long Beach, California. The pool was 3.5 feet deep at the start end and less than 5 feet deep at the wooden bulkhead turn. it was 10 years before anyone went 19 seconds in any pool. Fast is fast in any location or condition.

craiglll@yahoo.com
January 19th, 2007, 04:11 PM
I was wondering about how deep is the water when you actually begin to swim. I used to swim where the water was 3 ft. but in really I never really stroked or kicked until at least 4 ft. It seems that in most pools yuo would be in water at least 5 ft most of the time.

Frank Thompson
January 19th, 2007, 04:21 PM
How about discussing the turbulence and volume of water?

There is no stream of water following you into a wall to turn, just the turbulence created in the approach. If your streamline is nice and tight and you push off square to the wall, you will not notice very much past 3 feet from the wall where your (kicking) feet last were.

And quit being such babies about 3 feet of water in which to turn! In college, I regularly swam in park pools during Summer practice that were 24 inches or less deep at the wall in the shallow end. THAT was hard to turn on. But my fingernails were always nicely trimmed.

Deep water is faster? Probably. But consider this. In 1974, John Trembly set an American record of 20.066 for the 50 Freestyle in NCAA Championships held in Long Beach, California. The pool was 3.5 feet deep at the start end and less than 5 feet deep at the wooden bulkhead turn. it was 10 years before anyone went 19 seconds in any pool. Fast is fast in any location or condition.

Michael:

Yes back in the early 1970's there were a lot of Championship caliber meets held in facilities you describe. I believe the NCAA Championships of 1974 and 1978 held at Long Beach State might have been the last in those type of pools. Cleveland State University is a very deep pool in the diving section they use for Short Course Yard meets. I believe when they hosted the NCAA Championship meet in 1975, 1977, and 1979 everyone agreed that the pool helped swimmers with the fast times and American Records being set in almost every event.

Usually a deep pool like Cleveland State has superior gutter designs along with the depth resulting in minimal wave action and surface turbulence. In the older shallow pools of less that 5 feet, you will have choppy water because of the waves bouncing and usually those pools did not have the gutter system to dispose of the water at a fast rate creating a surface that will be slower for swimmers, affecting there progress rather than a nice calm deep pool of the same type that would not create these difficulties. This along with advancement of lane line technology in the 1970's made for faster pools. In many masters swim meets where swimmers are of different abilities, a swimmer will be fighting the backwash of the leading swimmers in a shallow pool. This is especially true when you see a 50 sprint and 7 seconds separating first and sixth.

When John Trembly went the 20.06 and set the American Record in 1974, he beat Joe Bottom who finished 2nd. Joe Bottom won this event the next 3 years and went :19.75 in 1977 at Cleveland State to set the American Record, so it was 3 years and not 10 years when someone would go 19 in any pool. Gary Schatz was the second in 1977 at a 19.95 and he was the second man to go under 19 seconds.

The significance of this swim is very equal to the record that Fred Bousquet swam in the 2005 NCAA Championships and went 18.74 for the NCAA and US Open Record. Both men broke the record by the exact margin of .31 (20.06 vs 19.75) and (19.05 vs 18.74) which is quite a large margin for a 50 Free. The one difference is that only one man went under the 19 time mark as opposted to two when the 20 time mark was broken. Duje Draganja went 19.01 just missing that.

Michael Heather
January 19th, 2007, 07:07 PM
Skip,

You are right, of course, I pulled the 10 year thing out of my butt. I think that was the first time a masters swimmer (Robert Peel) broke 19 seconds?

The Long Beach NCAAs were held at Belmont Plaza Olympic swim Stadium, built for the 1968 USA Trials. It has immense gutters which probably helped with the fast times. In that same meet, Jack Tingley also set an American record in the 1650, going 15:19.xxx (back in the days when three decimal points counted).

LindsayNB
January 19th, 2007, 09:07 PM
There is no stream of water following you into a wall to turn, just the turbulence created in the approach.

Are you sure about that? I thought it was widely accepted. Isn't this the same stream of water that people take advantage of when they draft?

Redbird Alum
January 20th, 2007, 09:42 PM
There is no stream of water following you into a wall to turn, just the turbulence created in the approach. If your streamline is nice and tight and you push off square to the wall, you will not notice very much past 3 feet from the wall where your (kicking) feet last were.

And quit being such babies about 3 feet of water in which to turn!

Michael -

Thanks for the advice...

I do tend to stay centered and squared, which puts me back through the "turbulence" I came in with (provided I have the lane to myself!). But given the earlier talk in this thread about taking your SDK out "under" the water near the surface, I was trying to ensure I had the right idea when I didn't have enough water to get "under" anything.

(I'm not unhappy with the shallow water, I swim in it all the time. I just want to make the best of it!)

Matt

Allen Stark
January 21st, 2007, 12:52 AM
Michael,there is water following you. You are right that there is turbulence.While this flow is not unidirectional it is primarily in the direction of motion. It is greatest at the surface(where one is as they approach the wall)so if you push off below 2 feet you will miss most of it.That is one reason you want to get at least to the flags before surfacing. You definitely want to push off at 90 degrees to the wall as any other direction will increase your drag. There was a study done when they were making one of the first "super pools" to see the optimum depth. They put colored crystals that slowly dissolved in the water at various depths and had swimmers swim over them. As I recall at 7 ft. there was no more motion of the colored water.

Michael Heather
January 21st, 2007, 01:29 AM
There is no stream of water following anyone swimming in a still pool. As the swimmer passes through, he displaces water and creates a turbulent zone both next to and behind him as the water seeks first to move away, then to fill the void he leaves. By the very action of swimming, one pushes the water away from the body with thrust developed by the hands and feet. So if there were a stream at all, it would be emanating away from the body, not following. So, push off directly through the turbulence, again with a tight streamline, and you will (1) benefit from the lower drag effect of the turbulence, and (2) get on with the rest of the race post haste.

I have also read (and heard) that the fsatest pools do not need to have a depth greater than 2 meters (6 1/2 - 7 ft). But the really deep ones make you feel faast. Or small.

scyfreestyler
January 21st, 2007, 01:42 AM
It always seems to me that I am swimming faster in the shallow end of the pool. The closer you are to the pool bottom the faster your eyes are going to perceive your travel speed. I suspect that lane ropes, pool gutters, and filtration/pump systems have more effect on actual swimming speed than pool depth.

Muppet
January 21st, 2007, 10:57 AM
It always seems to me that I am swimming faster in the shallow end of the pool. The closer you are to the pool bottom the faster your eyes are going to perceive your travel speed. I suspect that lane ropes, pool gutters, and filtration/pump systems have more effect on actual swimming speed than pool depth.

I find the exact same thing happening with me, and I came up with similar reasoning as to why. I think Michael is right in his "quit being babies" statement - I mean, if we're concentrating on how shallow the pool is, we're obviously not concentrating on our swims (maybe add another .1 to GoodSmith's tenth's list). But that's not to say the pool doesn't have an influence (Coral Springs vs HOF - SwimmieAvsPerson has a theory on this) on your swim either.

Allen Stark
January 21st, 2007, 02:58 PM
Michael,you are right about how to handle the turbulance,but there is a current going in the direction of the swimmer. It is primarily that water you point out is rushing in to fill the void left by the swimmer. Watch the 50 free at a meet. You can clearly see the waves follow a swimmer into the wall.
I read a study on resistance between dolphin kick on the side vs prone. There was no significant difference between the 2. This makes sense to me as what slows you in shallow water is the turbulance of your motion reflected back up at you. The turbulance from your SDK will ordinarily trail you and not be a factor in slowing you down.

craiglll@yahoo.com
January 21st, 2007, 03:12 PM
Something else that can really bother me is the pool temperature. I don't like swimming in mid-70s. I like it at least 79 degrees indoors. Outside, it doesn't seem to matter. Does anyone have in info on the effect of temp. I know that most pools don't even record it.

Someting about depth that I keep forgetting to put in . I am 6ft 6in. I have, rarely, hit my head in 3 ft pools as I am turning. In one pool where I used to swim in high school if the bulk head wasn't in the shallow(it was a 33 yard pool) I woudl hit everytime I turned in the full pool.