This is an excerpt from Coaching Volleyball Technical and Tactical Skills eBook by American Sport Education Program.
The jump floater serve is the same as the standing floater serve except there is an approach and jump to make contact with the ball. This type of serve allows the server to contact the ball at a higher point, making the trajectory of the serve flatter over the net and keeping the ball in the air for a shorter period, giving the passer less time to react and adjust to the serve. If a player is strong enough to throw the ball over the net overhand from the end line, then she can learn how to execute this type of serve. It is such an effective serve because when done correctly, the ball floats (without spinning) and has an unpredictable path, which makes it very difficult to pass accurately.
Position Several Steps Behind the End line
The player should take a position somewhere along the end line, from which she will move into the court to play defense. The player must be far enough behind the end line that she can make her approach and jump without going over the end line and committing a foot fault. The player should begin with the foot on the nonhitting side forward and the weight on the back foot. The ball should be held in both hands, about waist high and in line with and slightly in front of the serving shoulder (see figure 3.15).
Approach for the Serve
For a full three-step approach, the player steps forward with the foot on the nonhitting side (see figure 3.16a), followed by a step onto the hitting-side foot (see figure 3.16b), and then plants the nonhitting-side foot (slightly in front, closer to the net) and jumps up off both feet (see figure 3.16c). This is the same basic footwork and approach used in attacking the ball at the net, which we cover on page 88. An alternative is a two-step approach. From the same starting position, the first step is taken with the hitting-side foot, and then the nonhitting-side foot is planted so the player can jump off both feet.
Toss Slightly Toward the Net
The ball may be tossed either with both hands or with the nonhitting hand as you saw in figure 3.16, slightly out in front of the hitting shoulder as the server begins to take the second step of the three-step approach. For a two-step approach, the toss is on the first step. The toss should be 3 to 4 feet (.9 to 1.2 m) high and slightly toward the net so the server can jump up and reach high to hit it.
Jump and Swing
As the player lifts the ball for the toss, the hitting-hand elbow is drawn back high, which rotates the hitting shoulder away from the ball, as you saw in figure 3.16b. As the server jumps, and at the height of the toss, the hips and shoulders begin rotating around a central axis toward the net, followed by the elbow and the hand to the point of contact. The ball should be in front of and in line with the hitting shoulder.
Contact With the Ball
Throughout the entire motion, the server should focus on the ball and should see the ball being contacted. The contact point is on the back of the ball, slightly below center, with the palm of the hand. The wrist should be rigid and cocked back slightly to keep the fingers away from the ball. The server should hit straight through the ball, with the palm to the target throughout (see figure 3.17).
Follow-Through to Target, Landing on Both Feet
The follow-through of the hitting hand should be high and into the court, with the palm to the target, while the player lands balanced on both feet (see figure 3.18). The server's forward momentum should cause her to land inside the end line after contact with the ball. She will then continue to move into her defensive position on the court.