Yeah, I just didn't realize I could just use angle values by subtracting from 180, and simply could put speed (sides)
astern of the ship on the imaginary triangle, that is: if
the target is remaining on a constant bearing, then you both would have occupied a single point behind you (think of a collision in the past) --- it doesn't matter ahead or beheind since the problem we're trying to solve is just ratio in the triangle.
Since I read this thread:
http://www.subsim.com/radioroom/showthread.php?t=94608 I've been trying to use sliderule. After playing with virtual sliderules, I ended up getting a real Pickett 600ES (I should've gotten a longer one).
As I wrote in the above, a typical sliderule doesn't have "knot" nor "minute" scale so things like (ship length/seconds)*1.944 cannot be done in one no-brainer operation like in Hitman's circuler sliderule, but law of sine method is just fine
BTW, I like your rec book very much! I want one

Using lots of
external physical material gains immersion a lot. You can gather all information except range with real tools (have a stopwatch?).