I am currently building a 10' Seeker "S"glass-graphite Composite jig stick. I found that in positioning the reel seat it, I putting it farther up the blank than I usually do. My other rods in this genre have the reels positioned 21" from the end, but the new rod is at 27". This sparked a discussion among us about actually casting a shorter rod because of the reel placement.
Are you actually casting a shorter rod?
Don't you get more power because you have a longer lever at the butt?
This a boat casting rod, how does this compare to surf rods and steelhead rods for casting?

If you have a 10' blank to rod is 10' no matter where you place the reel seat.

A long rod is like a large lever ( a first class lever) with the fulcrum being the reel seat. If you were an extremely strong individual you could place the reel seat and thus your hand (the fulcrum point), very near the butt section. Your strength would overcome the mechanical advantage of the long arm between the tip and fulcrum point (reel seat and hand). This is not the case and the reel seat is usally mounted further up the blank to shorten the long lever and lengthen the short one - custom reel seat placement I think they call it. The rod still remains the same length.

Lou

Fishing rods are third order levers (second order levers if you're the fish, however). The fulcrum is the butt end. The reel seat is the "point of effort." This is true when fighting a fish, and still holds somewhat true for casting. Because the casting (reel) hand does not remain stationairy, a fishing rod never really approaches a first order lever.

Putting the seat up higher affords you a more powerful position from which to apply power, but the lever beyond the point of effort is now shorter.

For any rod, there will be a "sweet spot" for most anglers where they can apply sufficient power to move the remaining length of the lever beyond the point of effort. To high up and you have nothing to cast with, too low and you can't mount the power needed to cast whatever it is you have hanging off the end of the tip.

Best thing to do is tape up a seat on some snug shims and go out and throw it. Find that compromise point where you can best cast and fish it. Your brain will let you know when you've found it. It'll just feel "right."

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Thanks for the technicals! I have some time in the backyard testing casting before gluing the seat in place. I found that sweet spot where my casting takes a natural position by sliding the seat up and down as suggested. One by product was also finding a balance point with the reel on and finding this made the rod feel "lighter" because the rod wasn't as tip heavy.