Some Feedback:
Loaded up a single mission (TMO+RSRD) that had me patrolling just south of the Bungo Suido in late '42.
Target 1:
My initial 5 marks showed him going vaguely SSE, but I wasn't sure if maybe he'd made a turn at some point or was zig-zagging.
I put it down to inaccurate plotting on my part.
After I had marked points 6-9 I had a very good idea of his course. Obviously points 2 and 4 were aberrations. Possibly due to me not holding the beam on the target accurately.
I have worked out that at 30,000 yards a variance of 3 degrees gives you a possible error of 1700 yards!
So, obviously at long range you are just trying to get a sense of the targets general direction of travel.
As the range drops it becomes easier to get accurate plots and possible bearing errors have much less of an effect.
As the range dropped you can see my marks becoming a lot more consistent.
You can see the second plot I started when the target was close enough for me to get accurate stadimeter readings. It's pretty damn close to my radar plot.
And I sank the bugger right in the middle of my two plots.
Very satisfying.
Target 2:
I can see a pattern developing here

Again marks 1 to 5 are not consistent enough to give the targets true course yet, but they are good enough for me to decide which direction I need to head for the intercept.
As the range dropped I decided that marks 8-10 were probably close enough, so that's what I predicted his course as with the ruler.
As he got into visual range I would take occasional stadimeter readings just to check that he was still on the course I had predicted. I measured these, but as they showed him still on track I did not bother marking them.
In this attack I noted the time of my initial contact was 3.55am.
I made a visual mark exactly one hour later at 4.55am (not shown, I accidentally deleted it whilst deleting all my ruler marks and range circles

).
The distance between that mark and my first was 10.2 miles (IIRC) so I used 10 knots as his speed.
Worked like a charm.
You can see where I got him, very close to my predicted track.
I am very much loving this mod
Once I was close enough to get a stad reading I activated the PK and would watch the attack develop on the TDC (occasionally taking another range reading to keep it updated). It gave me a real good feeling for what was going on. Looking forward to JC's tutorial so I know what most of the dials are for
A thought: whilst switching off the radar between readings may make it easier to use because it remembers your last range and bearing, doesn't that also switch off your air search radar? Or is it always on regardless of the state of your surface search radar?
A question: my Gato had listed in the equipment screen an early SJ radar with a range of 20,000 yards. However, I was getting contact out to about 40,000. Is that to do with this mod, or have I FUBARED my game again?