Movement-related cortical potentials (MRCPs) have been used extensively in the literature to develop rehabilitation interventions for people with neurological conditions. In this pilot study, we recorded and extracted MRCPs using a water-based cap to determine whether water-based caps are effective. Five participants took part in the study, where their EEG was recorded during single-joint (dorsiflexion) and multiple-joint (sit-to-stand) lower limb movements. We were able to see clear MRCPs for both movement types with an average peak negativity (PN) latency of +22ms for dorsiflexion and +218ms for sit-to-stand. Similarly, the PN amplitude of -14.89μV was recorded for dorsiflexion and -43.54μV for sit-to-stand. These values were comparable to the values reported in studies using gel-based caps. Based on these results, water-based caps can be an effective way to produce robust MRCPs, which can have many advantages over gel-based caps.Clinical Relevance- The study provides clinicians with a more viable method of collecting EEGs and extracting MRCPs, thus allowing them to design more robust interventions for people with neurological disorders.