Wave-powered data buoys present an interesting opportunity for wave energy converters (WECs), with wave energy seeming a somewhat obvious power source for ocean monitoring buoys. Being small scale, and therefore relatively inexpensive when compared to large grid-scale industrial WECs, data buoys present a potential testbed for WECs; exposed to many similar challenges that large-scale projects face, at only a fraction the cost. However, wave energy at this small scale brings with it a number of challenges. With small scale devices experiencing exaggerated effects from friction and drag, the existing literature suggests that there is a split in the research community, with some advocating that for small scale devices, WEC solutions should be specifically designed for the small scale, such as triboelectric nanogenerators (TENGs); whereas others believe that scaling down a large-scale power take-off (PTO) is the more viable route to success for wave energy at the small scale. This thesis studies both a specifically small scale PTO, in the form of a rolling-ball-type TENG, which has negligible impact on the device dynamics, and a more conventional oscillating water column (OWC) PTO, which does affect the device dynamics. To account for changes in device dynamics, a free surface elevation estimator is designed and tested, to counter the common assumption that a wave measuring data buoy must be a true wave follower in order to accurately return measurements of the characteristic wave parameters commonly required by data buoy end users.