Background: Tactics in endurance disciplines is often considered by a analysis of distribution of velocity at a distance. Long-distance swimming (800m, 1500m) is a discipline perfectly located in the above definition. Thus the purpose of the paper is to deepen knowledge on sport tactics based on the distribution of velocity by athletes training swimming at the highest level.Material/Methods: The research material comprised finalists of the swimming race on the 800 meters at the Olympic Games in Beijing (2008) and the World Championships in Rome (2009). Data on the average speed for the entire distance and average speed for the 50-meter segments were analyzed. The average speed for the "halves" (350m and 400m) and "quarters" (150m, 200m, 200m, 200m) was calculated, and the specific "velocity differences index" was also identified (VDI). To illustrate the results better, a linear and non-linear regression equation was used.Results: The results show that the top athletes both of the Beijing Olympics and the World Championships in Rome maintain consistency of the pace; deviations from the average velocity are low, and increasing speed happens at the finish. The analysis of non-linear regression equation confirms this observation. The second "half" of the distance is covered by the best swimmer at higher speeds compared to the first part of the distance; the analysis of "quarters" indicates that the middle one is the slowest. The values of VDI for "halves" have the lowest values in both races for the best swimmers.Conclusions: The analysis of results justifies the conclusion that primarily it is the constant pace of the race that gives a chance to obtain a high result. The ultimate way in which the race is to be executed depends on athlete's individual predispositions; however, maintaining a constant high speed without speeding up at the finish proved to be an effective tactic in the case of one of the top athletes in both races.