Are there any height or weight requirements for rowers and coxswains?

Not really. Although rowers in some boats (classed as lightweights) must be within a weight limit (typically 130 pounds for women and 155 pounds for men), there are no upper or lower weight limits for rowers in most boats. Although height can be an advantage for rowers, strength and endurance are more important. Coxswains are usually small and light. The best coxswains are smart, light, verbal, confident, and have some rowing experience.