Be assertive in adjusting yourself or informing others if you don't have a clear sightline of the signer. This is usually done by pressing the shoulder of the person blocking your view. First, adjust your position. If this doesn't work, adjust the position of the person blocking your view by pressing their shoulder in the direction you want them to move. The person should change their position without needing to look at you. Remember, don't tap someone's shoulder unless you want to get his or her attention. What should you do if you don't have a clear sightline of the signer?
1) Adjust your position
2) Press the shoulder of the person blocking your view
3) Tap someone's shoulder to get their attention
4) Inform others about the situation