zoom-zoom, I used to be a coxswain (basically small person steering boat/barking orders in crew) and I had this EXACT problem with someone in my boat. At the time I was 14 years old and the man barking orders at me was at least 60 or so. Actually, my father was in the boat too. The man would belittle my steering/skills (despite the fact that my steering took my girls boat to #2 nationally ranked) and I was constantly recognized in races as a skilled coxswain.
Now, keep in mind I was a teenager and at that point it's difficult to stand up to someone much older than you... I felt like an elementary school student being yelled at in class.
Finally I screamed at him: "enough. you do your job, I do mine." as we were racing. Found out later that another in the boat pulled him aside too to tell him that he was out of line. I was grateful that my dad never came to my rescue because it would have made me seem like a scared child. After that he shut up.
The funny thing is that he'd yell at me about steering but he was rowing so technically wrong (digging really, really deep) that he was throwing off the keel of the entire boat and actually screwing us up. Irony!!
Sorry for the long story, just wanted to tell you that I know exactly how you feel and it totally sucks. It's hard to stand up for yourself in this kind of situation.
Life goes by pretty fast. If you don't stop and look around once in a while, and do whatever you want all the time, you could miss it.
2010 Fuji Roubaix 1.0
2007 Fuji Absolute 2.0