Open water swimming consists of a mass or wave start on land or in water and a finish on either land or in the water. Finishes in the water are usually designed as per FINA rules where the time is taken when the swimmer touches the touch pad above their heads.
Start times are easily determined as wave starts as swimmers within categories leave at the same time. There may be numerous waves to break up the swimming groups for safety management. A finish on the beach is easy to setup as per the diagram below. A finish in the water is more complicated and requires a large array of side antennas projected in front or above the swimmers wrist. This requires a floating gantry design to be anchored in the water.
The transponder are worn on both wrists and picked up when the swimmer reaches up to touch the touch plate above their heads. The transponders can be reuseable Hutags or disposable tags using an integrated adhesive wrist band with transponder.
Ocean or lake swims are relatively easy to time using just a single Ultra4 system and a combo of Ultramats and side antennas.
Swimming Events Using RFID Race Timing Systems
Rottnest Channel Swim (AUS), Lorne Pier to Pub (AUS)