Rudder alignment

It is not clear to me the best way to determine the location on the trailing edge of the rudder to measure for proper alignment. Specifically, the procedure say that once you pick the location on the leading edge (near or at the hump) for both rudders, to go “straight back” for the trailing edge measuring location. As simple as the words “straight back” are, there is nothing on the hulls or rudders that give a parallel or perpendicular reference, except the rudder pin axis. Because the rudders are not parallel to each other in the down position (from top to bottom), the trailing edge location will have a bearing on the alignment results, and will vary depending on what is “straight back”. It would seem that the rudder rake, and the average attitude of the leeward hull should define “straight” but what is that?

Probably making too much out of this.
Tips and suggestions welcome.

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Russ

You got that right.

"Straight back" is "straight back" - level, horizontal, whatever - you're only moving nine inches. Whether you're off by 10 or 15 degrees doesn't really matter.

The rudders are (should be) fairly close to vertical (side-to-side) when the boat is level (side-to-side). Moving an inch or so up/down the blade is not going to make that much difference.

Chances are (unless you're a fanatic about getting the slop out) that there's more wobble/slop in the system than the difference in measurements you're taking.