Is the "S" stroke revelant any more???

I have been tethered and have taken the tether to the limit. I have stayed 3 feet from the wall and it is very tireing for sure. Does it give you any advantage in a race I don't know but we are heading to Mexico for another 2 months in March. I will take a tether and take make videos to post.

In other simple terms..you can't really apply hydro-dynamics of rigid structures to those of human motion. Example 2 – Take that Mississippi paddle boat, extend the paddle 1/3 again in front of the boat, teach it proper EVP (Early Vertical Paddle) and have it pull/push the paddle past amidships ...and it's a different story. Sculling the hand at 14,000 RPM provides the same effect as does a propeller, but it may cause other problems.

Yeah, that's the other problem. As if the aerodynamics (or hydrodynamics, if you insist) were not difficult enought to get a grasp on, human physiology has to rear it's ugly head. There's a constant tradeoff between the ideal stroke from an aerodynamic standpoint and the ideal stroke from a biomechanical standpoint.

The US Navy and there new torpedos that will move through water at the speed of sound. There are absolutely no such things as torpedoes that move through the water at the speed of sound. The speed of sound in air is ~770 miles per hour (or 344 m/s) (depending upon relative humidity and temperature) and significantly faster in water. Russia developed a supercavitation torpedo in the 70s that reached speeds of approximately 300 knots (or ~340 mph). That's only about one tenth the speed of sound in seawater. The picture in geochuck's post is of this Russian "Shkval Rocket Torpedo" and there are several websites that dispell the myth that these weapons approach the speed of sound. This discussion is very fun for someone of my limited intellectual capacity, but limitless affection for physics and mathematics (read, I am a geek, just ask my wife)! Any discussion of peak athletic performance in water has to involve both human kinematics and hydrodynamics. The hydrodynamics portion of the equation is far too complex to solve by hand and must be estimated by computational fluid dynamics (CFD). So, a fluid mechanics person could probably develop a model of the ideal swimmer, but it's another matter entirely to assume that each swimmer can manipulate and/or coordinate their body to fit the model. The bottom line is that the swimmer must minimize drag along his/her body, but maximize drag on the pulling surfaces (forearms and hands). I've only been swimming for about a year now, so I won't claim to be anywhere near an expert about stroke mechanics, so I won't begin to claim I know how to maximize drag on my hands and forearms while minimizing the drag along my body. I do know that each time my coach makes a change in my stroke, I can feel the difference! I don't know if I contributed anything to the post, but I certainly do like to hear myself talk:)!

The speed of sound in air is ~770 miles per hour (or 344 m/s) (depending upon relative humidity and temperature) and significantly faster in water. Yeah, about 1,500 m/s at standard temp and pressure. That would be one fast torpedo! Here's an article about the supercavitating torpedoes: www.popsci.com/.../de669aa138b84010vgnvcm1000004eecbccdrcrd.html I don't think the torpedoes are quite that fast, but it does mention the Navy have successfully launched a supercavitating projective that surpassed the speed of sound underwater. Pretty amazing!

It is a myth that the Shkval travels faster than the speed of sound. It exceeds 200 mph, but gets nowhere near 700 mph. The Popular Science article only says that the US Navy has tested a prototype, but it never says that prototype approached the speed of sound. Geochuck, the military.com article you linked to dispels the myth that this weapon approaches the speed of sound!

Yes the Shkval is a very slow 253 mph underwater. Irans torpedo maybe a fabriction??? Do you really think this. The Iranians are buying Shkvals from the Russians including the submarines that are deploying them. They have not developed their own supercavitating weapon. The only information I've heard about US supercavitating torpedoes is that we have tested some prototypes, but they are nowhere near as fast as the speed of sound in air, let alone water. You're right, this has no bearing on our ability to swim. Perhaps if we could expel enough air to envelope our body, we could reduce drag significantly. Hmmmm, sounds like hypoxic work to me!:D I couldn't resist the urge to reference another controversial topic.

Sound of speed in Water is something like 3000 Mph or is it 3000 knots per HR??Knots notes: Knot is already a unit of speed (equal to one nautical mile per hour) And if you want to calculate the speed of sound in water just follow the simple empirical equation below for the speed of sound in sea water: c(T, S, z) = a1 + a2T + a3T2 + a4T3 + a5(S - 35) + a6z + a7z2 + a8T(S - 35) + a9Tz3 where T= temperature in degrees Celsius, S = salinity in parts per thousand and z = depth in meters, respectively. The constants a1, a2, ..., a9 are: a1 = 1448.96, a2 = 4.591, a3 = -5.304×10-2, a4 = 2.374×10-4, a5 = 1.340, a6 = 1.630×10-2, a7 = 1.675×10-7, a8 = -1.025×10-2, a9 = -7.139×10-13 But back on topic… good observations Coach T.

In simple terms..you can't really apply physics on land towards hydro-dynamics. I agree about mass and acceleration providing greater force...but the force has to applied effectively towards the water...not slipping through it. Example...A Mississippi paddle boat with enormous horsepower moves huge volumes of water and goes nowhere fast. Take the same vessel...replace the paddles with propellers...and it's a different story. Sculling the hand provides the same effect as does a propeller. It's the difference between slipping and gripping.

Bubbles around the body is what we need so we can travel faster through the water. This is a picture of a body moving at 3 times the speed of sound underwater. Bring on the bibbles.