One of the advantages of running this web site is access to some very smart people. One of the things I picked up from these smart guys in the last year is that fin settings have a lot to do with what happens at the wakes and on the way to the ball line. Traditionally most of us all talk about fin settings only in terms of what happens at the ball.
I am not an expert on this subject but what I know and how I think about it is as follows.
The more fin you have in the water the less the ski slides down the course. If all you care about is cross course speed and direction you would think you want a LOT of fin. 2.530 deep and 6.950 long! Ok that is an exaggerated amount of fin but you would be surprised how much fin some pro skiers run. I tried the settings given to me by a pro a few weeks ago and it was 2.535 deep. Typically one of the good things about a lot of fin is a very smooth off side finish assuming your center of mass is pretty far forward.
Unfortunately too much of a good thing is a bad thing. The one thing that I notice with too much gross surface area is that the load at my core is more than I can deal with. Because the ski is sliding with the boat less=> the boat is simply pulls my hands way from my core. The ski simply has too much grip at the wakes. Take away some depth or length and the side slip of the ski absorbs more of the boats power and I can stay more connected.
The other bad thing about too much fin is it increases drag. So if you are mega strong and have pro skier skills more fin may get you out to the ball early and then slow you down fast. On the other hand a smaller fin will make you faster cross course but will slow down less.
Take all this in addition to the old rules of thumb about how to adjust for the turns and you will see that there are a lot of choices and they are all compromises.