Concept2 is the gold standard, and it's not even the most expensive. It's the only machine competitive rowers use, from high school to the olympics. C2 supports

Concept2 is the gold standard, and it's not even the most expensive. It's the only machine competitive rowers use, from high school to the olympics. C2 supports their machines to an insane level, going so far as to provide replacement parts all the way back to their first machine from 1981.