First off, here are a couple of items that might be worthwhile sharing:
Items needed to navigate with SH4-
1) Small protractor
2) Scale with cm/mm on one edge and 10th of inch on the other.
3) You don't have to D/L special plot sheets all you need is a piece of blank paper. See above, I show my current position just SW of Lambay Island on the SW of Formosa (Now Taiwan).
Use the formula
Long cos Lat to convert your scale mm, 10th of inch, or cm into lat and long. Here's how:
example: in above pic my last position is Lat 22° 18'N, 120° 19.9'E. I happen to be using 10th of inch as nautical mile on my plot, therefore 19.9' x cos 22° = 18.5 tenths of inch (1.85") east of 120° meridian indicates my longitude. Since I'm using 10th of inch as my nautical mile, Latitude will be read directly off the 10th of inch scale.
4) Nautical Almanac for war years 1941 to 1945
5) Formulae for determining the calculated height of the body and it's ground position azimuth:
1) Hc = asin [( sin Lat sin Dec ) + ( cos Lat cos Dec cos LHA )] and,
2) Z = acos [( sin Dec - sin Lat sin Hc) / (cos Lat cos Hc )].
In the above pic I've shown the math envolved in determining the Hc and Z using the above formulae. If you'll note once the Greenwich Hour Angle (GHA) of the sun was obtained, since I'm in East Longitudes, I must add my Assumed longitude to the GHA to obtain my Local Hour Angle (LHA) as a whole degree (317° in my example above). if I were in West Longitude, I would subtract my longitude from the GHA.
The increments of 120° 20.6'E =
20.6 x cos 22 = 19.1 (1.91") east of 120° on my plot indicates my assumed position. From this spot I construct a line 134° toward the sun.
Since the calculated sextant altitude (Hc) was larger than what I observed (Ho) the line of position (LOP) will be away from my assumed position. The rule of thumb = HO MO TO ( if Ho is More then the LOP is Toward the body).
On the plot sheet above, you'll also notice that I did a 45°-90° running-fix on Lambay Island. It's a timed event and it put me about 1.5 nm off and as you can see that it put me about 1 nm SE of my Sun sight LOP...so, what are you going to believe--your lying eyes through the TBT or the sun sight?
Pic below show my position on the F5.
One final thought about making your own plot sheets. Accuracy starts to fall off beyond 2° (120 nm) so you'll have to make more of them.
Cheers,