Are you only supposed to get blisters on your inside hand? I have one on my outside hand on my fingers which has never happened before. I also have a tendency to over grip and feather with my outside hand. Would that have anything to do with it?
I think it’s common to get them equally on both hands although because of feathering they could potentially be worse on your inside one. If you’re over gripping with that outside hand that’s probably going to play a bigger part in it than feathering would. With feathering you’d have blisters on your palms or where your fingers meet your palm whereas what you’ve got sounds more indicative of just holding on to the handle too tight. When you’re out, try to remind yourself to keep your grip loose – you should be able to wiggle your fingers on the recovery and on the drive, you want to feel the weight in your fingers but you don’t want to be holding on to the handle for dear life.
Over gripping your hands usually means you’ve got a lot of tension in your shoulders/upper body too. If you remember, ask your coxswain at your next practice if she can periodically say something to remind you to loosen your grip, relax the arms and shoulders, etc. Also make sure you take proper care of your blisters. Soap, water, and band-aids. It hurts like hell but it’s better for it to sting for a bit than develop an infection later.