Substitute

From Tandem Couples: Lead couple makes an arch and backs up while the trailing couple moves forward ducking under the arch. No one changes facing direction. Ends in Tandem Couples.

Other formations are possible and the caller is responsible for making it obvious which dancers are to arch. Usually they are active or designated. Depending on the facing directions of those making the arch, they may move forward or backwards. Those going under the arch may move forward, backwards, or even sideways. Examples: From a Trade By formation, Centers Arch and Substitute Over The Ends. From a Squared Set, Heads Touch 1/4 and Substitute (Over The Sides). From a Galaxy, Centers Substitute Over One, or Those In The Wave-Based Triangle, Substitute