deep pools

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.

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.

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.

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 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.

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)?

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.

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.

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).

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.