We usually row to tens, we tend to muscle up. Are you relaxed when you row. Do you feel you unfold your body like a whip? How do you learn to do this? How do you know when you are doing it right?
When your body is loose you are better at generating at snap and generating more power. The more relax on your stroke, the more elastic and dynamic you can be and the more powerful it will be.
You need to grip your oar like you hold a pencil, not squeeze it it as if you were choking a chicken. The most common physical cause of underperformance in rowing is over- tightness.
Over-tightening muscles to produce power actually creates a loss of power and accuracy. Tension hurts coordination.
Relaxation happens when you stop creating tension.