Angle of mast

I know we like to rake the mast back to close the gap between the foot of the sail and the board(nose to tail) but does anyone have any theories on the best angle of the mast. ie the angle side rail to side rail. 90 degrees or a tighter angle to the rail

I was under the impression that raking the sail in the fore-aft direction depends entirely on the centre of effort of the sail, and what angle it needs to be raked to align that force with the centre of lateral resistance of the board (i.e. mainly the fin once planing).

Which explains why I have two sails of the same size but different brands/ages, and one likes to be more vertical than the other.

Closing the gap is secondary, and not the original aim of the exercise.

But back to Old Salty's original question which was regarding angle in the other direction (across the board rather than along it).. It's a balance between presenting the most sail area to the wind (rig vertical), and angling the rig over you so that it carries some of your weight and gets it off the board.

So, I'd think that raked over you would be the answer, but just how much is a good question, and probably varies depending on what you're doing / riding and the conditions.