exchange noun - An exchange (or a relay exchange, change-over, or takeover) is the change from one relay swimmer to another in the course of an open water swimming relay. It is the point where one swimmer in the water stops his leg and the other begins the next leg of the relay.
Exchange Rule Examples
Channel Swimming & Piloting Federation
The change-over/takeover from one swimmer to the next in a relay should take place every 60 minutes with the new swimmer entering the water on a signal given by the observer. During the take-over the new swimmer must enter the water from behind & swim past the preceding swimmer. The previous swimmer must then exit the water as quickly as possible. The change-over should take no more than 5 minutes.
Catalina Channel Swimming Federation
On receipt of a time signal, the changeover to the new swimmer will be made as soon as is practically possible (should be within one minute) after the previous swimmer has completed his/her respective leg, but under no circumstances more than five minutes after the end of the previous swimmer's leg. In a takeover, the new swimmer must enter the water behind the preceding swimmer, and swim past him/her. The new swimmer must touch the preceding swimmer.