Although aquatic activities are commonly used in special education classes in Penang, Malaysia, there are no specific modules and training that can be used as guidance for the special education teachers conducting these activities. This drawback has contributed to teachers' low self-confidence when conducting their teaching and learning sessions, which can affect their students' level of comprehension and progress in their lessons. Therefore, this study focuses on the Aquaexplorers module to discover its effect on the self-confidence of special education teachers in Penang. A mixed-methods approach is used with 120 special education teachers on the implementation of the Aquaexplorers module. A pre-post test consisting of a questionnaire was given before and after the course to investigate the effect of module implementation on the participants' self-confidence in conducting water activities. A semi-structured interview was performed to acquire supportive qualitative data, analysed using NVivo. Results of a paired t-test showed that there is a significant difference (p < 0.05) between the pre- and post-test in participants' levels of self-confidence, and results from the analysis of the interview data using NVivo supported the quantitative findings, leading to our rejection of the null hypothesis.