Here are some pictures describing the three steps of the stroke underwater. At the top we see the Catch.The purpose of the catch is to get those fingertips pointing down, and the palm facing the feet, with the elbows close to the surface, on top of the hand. At the bottom left we see Michelle Williams, from Canada swimming at the Pan Am games. We can see she is at the Pulling stage of her stroke. The elbow stays right on top of the hand as the hand pulls towards the feet. Finally, at the bottom right we see Alexander Popov from Russia. If you look at his right arm you can see how the arm has extended so that the hand is past the hips, notice also how close the hand is to the leg as it is getting ready to exit.