speedboat
A small, very fast motorboat used for racing or fun.
A speedboat is a small, fast motorboat built for racing across water at high speeds. Unlike sailboats that rely on wind, speedboats use powerful engines to zip across lakes, rivers, and oceans, leaving a wake of white foam behind them. They're designed to be sleek and light, cutting through water the way a sports car hugs a racetrack.
You might see speedboats pulling water skiers, racing in competitions, or simply cruising for the thrill of speed. Some speedboats can reach speeds over 100 miles per hour, fast enough that the front end lifts partly out of the water as they accelerate. The ride feels completely different from a regular boat: bumpy, loud, and exhilarating as you bounce over waves.
It specifically refers to boats designed for going fast, not just any boat that happens to move quickly. A fishing boat with a motor isn't a speedboat, but a racing boat with a streamlined hull and powerful engine definitely is.