You will probably get a number of different inputs on this. I think that 7 times across would be about right if you were using a 5500-series reel, but with the larger 6500 you are probably looking at about 5 "bars". If you are using monofilament (which floats), beyond that you are basically putting a progressively bigger bow in your line rather than getting much additional depth. If you are using Power Pro or some other line that is not especially buoyant then more line out may give you more depth, but I'm not sure about that.