IPA: /ˈpaʊərˌboʊtə/
KK: /ˈpaʊərˌboʊtər/
A person who participates in the sport of driving or racing powerboats.
The powerboater skillfully navigated the waves during the race.
Powerboater → It is formed from "power" (from Old French *poeir*, meaning strength or force) and "boater" (from "boat" with the suffix "-er" meaning a person who). A powerboater is a person who operates a boat powered by an engine, emphasizing the strength or force of the boat's propulsion.
Think of someone who uses the 'strength' ('power') of an engine to operate a 'boat' — that's what a powerboater does.