noun - Ziplining is the act of grabbing another swimmer by the ankles or legs in order to unsuspectingly pull the other swimmer back and gain an unfair (illegal) advantage in open water races. It is grounds for a yellow card (or yellow flag) (caution) or a red card (or red flag) (disqualification). Zipling is one example of physicality in open water swimming competitions.
The young woman lost ground when she was zip-lined by another competitor towards the end of the race.
Yank, pull back, pull, impeding