have the side mount on my 16' alumaweld drifter but it takes 35# to stop it in flows around 3,000 cfs or above. In these cases when anchoring in faster water, I do get the side to side depending on where the weight (ie front passenger) is.

Some guys who sit on anchor will install a 10# off the bow. I always keep my oars in the water thinking that it helps stabilize the side to side some. although logically you would think the opposite?