Question for Hamdenpro
As for drag coefficient, it really depends on two things:
1) the type of ball being used as, I am sure you are aware, the number, and size of the dimples, as well as the density and materials used will all affect trajectory and velocity. Putting all that aside, The drag coefficient (Cd) is equal to the drag (D) divided by the quantity: density r times half the velocity V squared times the reference area A. Keep in mind, choice of the reference area will affect CD or drag coefficient; and more importantly.
2. Depends on whether my brother is wearing my dresses again.
As for your second question, I do use magnetic north since I am using a standard compass and not a GPS or digital unit. There is no need to share "my" declination equation. Since: a) I do not have one; and b) It would not help you as magnetic declination changes over time and with location.
As I am under constant moderation, any declination I state now will have changed by the time this reply gets through moderation.
My suggestion would be to view Mr. Hope's website links. I am sure he has prepared the most up to date maps of each course. On the bottom right of each map should be a key which will state the declination for that area.
Vous e'tes tout a' fait le bienvenu.
EDIT: Now that my reply has posted, I can affirmatively state that, as of 10:23 EST in the Northeast of the USA, at the exact place I am presently standing, which is next to my brother, who looks wonderful in my gown, the Magnetic Declination is 15 degrees West. As I am in my back yard, I do not believe this will help you unless you are simply playing through.