I have been studying videos of swimmers and find what was once called the "S" stroke has almost disappeard.
I have noticed that flyers use it. But crawl swimmers have modified it so much that it is almost gone.
Has it been replaced completely or was it an optical illusion? Did underwater film show us it did not exist.
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Former Member
I understand what you're saying with the "quiet water" thing. When you start pulling, you accelerate the water behind your hand. To create additional propulsive force you need to find additional quiet water to accelerate. If you just continue to push on the already accelerated water you don't produce any additional force.
It has always seemed to me that many people in the swimming world use a rather simplistic if not misguided model of swimming physics. It seems like viscosity and drag are more appropriate tools for thinking about swimming than acceleration of mass. I think you will find that if you move your arm through water there will be plenty of force due to drag even after you have supposedly accelerated the water behind it. Another way to experiment with this is to put your arm in a horizontal position under the water and lift it up out of the water, observe how much of the water rolls off your arm instead of moving with it. Or stick you hand just under the surface and then throw some water up in the air, compare the force needed to accelerate the handful of water to the force needed to move your flat hand through the water at anything like an equivalent speed. I am open to being proven wrong but I don't think acceleration of mass is the dominant force to be thinking about, and certainly the idea that force goes to zero after you have accelerated the water behind your hand is just plain wrong and easy to disprove with a simple experiment.
I understand what you're saying with the "quiet water" thing. When you start pulling, you accelerate the water behind your hand. To create additional propulsive force you need to find additional quiet water to accelerate. If you just continue to push on the already accelerated water you don't produce any additional force.
It has always seemed to me that many people in the swimming world use a rather simplistic if not misguided model of swimming physics. It seems like viscosity and drag are more appropriate tools for thinking about swimming than acceleration of mass. I think you will find that if you move your arm through water there will be plenty of force due to drag even after you have supposedly accelerated the water behind it. Another way to experiment with this is to put your arm in a horizontal position under the water and lift it up out of the water, observe how much of the water rolls off your arm instead of moving with it. Or stick you hand just under the surface and then throw some water up in the air, compare the force needed to accelerate the handful of water to the force needed to move your flat hand through the water at anything like an equivalent speed. I am open to being proven wrong but I don't think acceleration of mass is the dominant force to be thinking about, and certainly the idea that force goes to zero after you have accelerated the water behind your hand is just plain wrong and easy to disprove with a simple experiment.
