This exercise builds off of the Teammate Drag. It is best done for a 25 at a time. Here is how it works. Swimmers are partnered, with one swimmer pulling (sprinting) and the other being pulled. Somewhere between the 15m marks, the trailing partner pulls the leading partner’s leg, attempting to slingshot to the lead. They then sprint to the wall. The kids love this exercise, and it really got them going pretty fast.
Here’s a video example: