4 x 50m Obstacles Relay
Originally designed to simulate swimming while diving through waves the obstacles relay consists of each competitor sprinting 50m and diving under two obstacles (commonly referred to as gates), which are positioned at 12.5m and 37.5m. As the competitor approaches the gate they will dive under and then resurface either by swimming under the gate or by diving to the pool floor and kicking off at an angle, resurfacing beyond the gate.
4 x 25m Manikin Carry
The aim of this event is to tow an 8.5 stone orange manikin (commonly referred to as a BOB) over a distance of 100m. Each competitor tows the BOB 25m keeping its head above the water. This is commonly done either using an extended arm tow or by swimming front crawl with the manikin on the competitors back. After 25m the competitor then passes the manikin to the next person in the relay until all 4 competitors have completed their distance.
4 x 50m Medley
This event consists of 4 different 50m swims. Starting from a dive the first competitor sprints 50m then touches the wall. When they touch the wall competitor two dives in wearing racing wins and sprints another 50m, again touching the wall. Competitor 3 will then dive with a rescue tube and sprint 50m to competitor 4. Competitor 4 starts in the water, wearing fins, and when competitor 3 touches the wall takes the strap of the rescue tube and places it around them. Competitor 3 then grabs the other end of the rescue tube and competitor 4 tows him 50m. Competitor 3 is permitted to kick to aid competitor 4 in their swim.
These events are governed by the latest RLSS short course or long course rules depending on the size of the pool.