The biomechanical analysis of swimming always faced impeding factors of measurement in the aquatic environment. Our current knowledge of swimming locomotion is very much owing to employing video cameras to capture the body kinematics. Nevertheless, the recent improvements in wearable inertial sensor technology and signal processing techniques offer us a whole new range of measurement setups that were not realizable beforehand. The principal aim of this paper is to present the inertial sensor based systems that are used in the study of swimming biomechanics. In this manuscript we briefly introduce the other existing technologies used in analysis of swimming and the necessity of having an easy to use, reliable and affordable system. Then we highlight the application of inertial sensors in estimation of temporal phases of swimming and also estimation of performance metrics. The perspective of the inertial sensors applications in the swimming studies is eventually discussed. Our concluding remarks advocate the potentials of inertial sensors as a tool for coaches to design the optimal personal training plan for trainees.