Background: Aquaculture is a rapidly growing fisheries sector in the world. A maximum of fishing industry workers has musculoskeletal problems, commonly involving the low back (92.4%). Heavy physical activity, such as weightlifting, repeated movements and prolonged periods of static posture, are the main causes of mechanical nonspecific low back pain. Objectives: To find out the effectiveness of water-based exercises on mechanical low back pain among aquaculture workers. Method: The study design was a pilot study. 20 aquaculture workers with mechanical low back pain were selected from Marakkanam Taluk of Tamil Nadu in India and water-based exercises were given for 6 weeks. The outcome measures (Modified Oswestry Disability Index, Numerical Pain Rating Scale) were measured in pre and post-test for 6 weeks. Result: The statistical analysis was done with paired ‘t’ test within the group, with the value of significance (P< 0.001). The ‘t’ of MODI is 11.753 and the ‘t’ value of NPRS is 14.333. Conclusion: The 6 weeks study concluded that water-based exercises show more significant improvement in reducing mechanical low back pain among aquaculture workers.