Abstract: Practical electric-powered propulsion systems, associated operator-control systems, and modification methods enable conventional surfboards (and similar small watercraft) to be converted for water-jet propulsion. Wireless controls are integrated with wearable marine accessories such as modified neoprene or fabric gloves, armbands, wristbands, hand straps, or gauntlets. Safely immersible, wet-swappable high-power battery packs facilitate extended use of electric propulsion in surf. Compact integrated electronic control units incorporate motor controllers, wireless receivers, and control logic. On-board power, propulsion, and control components are positioned and installed to avoid disrupting the shape of the watercraft body so as to minimize added hydrodynamic drag and perceived differences from a traditional unpowered version of the watercraft in appearance, balance, or performance.