A modular, weight-shift controlled watercraft device is disclosed which includes: a modular board removably attachable to a power system. The power system includes a modular power supply system, and a modular propulsion system. The power supply system includes a housing including a battery. The propulsion system includes a modular strut, a modular propulsion pod, and a modular hydrofoil. In one embodiment, the power supply system is removably and mechanically attachable directly to the propulsion system.