Why do this drill?
Doggy paddle is used to encourage you to maintain a high elbow through the pull phase and to get used to the feel of using the forearm as a paddle. This is a good drill to do to correct or develop your catch and pull phases of your stroke.
How to do this drill
Doggy paddle is full stroke swimming but with your recovery phase taking place under the water. As you finish your push phase do not bring your elbow and arm out of the water but return your forearm to the pull phase position and then bring the hand forward, roll, extend so that the arm is a hands width below the surface of the water and begin the next stroke. This drill encourages an Early Vertical Forearm and an awareness of using the forearm as a paddle. Keep your head in the water, in a neutral position, breathing to the side as required.
Perform the drill as described but keeping your head just out of the water, eyes facing forward.