Deafness is a medical condition in which the sense of hearing is lost (deficiency or loss of hearing ability). Individuals with hearing disability require special assistance in carrying out start exercises such as the swimming grab start model and light aids. The purpose of this study was to determine the effect of reaction speed training using assistive devices on the ability to start swimming in deaf children aged 13-18 years. The method used in this study is a quasi-experiment. Population and sample amounted to 20 deaf children aged 13-18 years. The instrument used was a swimming start skills test. Data analysis and hypothesis testing used comparative analysis techniques using the t test (mean difference test) with a significant level α = 0.05. The results of the study concluded that there was an effect of reaction speed training using assistive devices on the ability to start swimming for deaf children aged 13-18 years with t count 17.06, Std. Deviation 1.64 with a significance of 0.000.