Electric boat thrust and battery capacity** determine whether a vessel can deliver the required push while maintaining usable runtime. Thrust is a function of motor power, propeller design and system voltage. Battery capacity (kWh) governs how long that thrust can be sustained. Confusing the two leads to undersized packs that force early power reduction or oversized systems that add unnecessary weight and cost. This technical briefing explains the quantitative relationship between electric boat thrust and battery capacity, provides sizing formulas

Speed is the dominant variable controlling energy use on any electric boat. The relationship between electric boat speed vs energy consumption is strongly non-linear: hydrodynamic drag rises rapidly with velocity, so the power required—and therefore the energy drawn from the battery—increases far faster than a simple linear proportion. In 2026 this principle remains the single most important factor for range prediction, battery sizing, and operational planning. For displacement and semi-displacement hulls the classic approximation holds: P \propto v^{3} where P