The authors analyzed how using 2 types of fins altered the velocity ( v ) and fatigue indexes (FI) of lifeguards during mannequin carries. Ten participants performed 3 trials of 25-m mannequin carries at maximal v while barefoot and while wearing flexible and fiber-type fins. A swim-sensor speedometer was used for measuring v. Mean v during 2-s periods was computed in the beginning, middle, and at the end of the event. The slopes of v and FI were computed for the first and second halves of each trial as well as for the total time required. After it had been established that the data distributions were normal, repeated -measures ANOVAs were calculated for each dependent variable. Results confirmed that mannequin carries while barefoot at each point had significantly slower v than when using either type of fin. Declines in v across the 25 m tended to be greater when the lifeguards did not use fins, and the slopes tended to be smoother when they used flexible fins. Using fiber fins enabled participants to maintain the same v from the beginning to the end of each trial. No significant differences were found across conditions for v slopes and FI.