There is absolutely no magic parameter that will make the speed estimate more accurate. It is perfectly accurate if your observations are perfectly accurate. Unfortunately, the stadimeter is not a perfect method of determining range. The further away the target is, the worse your range measurement is going to be. Subject to errors in the ID manual, there will be errors there too, which will render the estimate unreliable.
The much heralded speed estimate method actually isn't very useful at all, due to those realistic limitations. It is not a bug in SH4. It is a bug in the methodology of obtaining target position through the periscope. And it is entirely realistic.
I would recommend not using the speed estimate method unless there is no other way to determine speed. The best way is to mark two radar positions on the nav map three minutes apart. Measuring the distance between the points, the number of hundred yards is the target speed. 750 yards would be 7.5 knots. If you insist in using the lousy metric claptrap
, measure two positions three minutes fifteen seconds apart and the number of hundred meters is the speed in knots. This is accurate and you can rely on it.
By the way, get in close. 1800 meters is okay for a big target like a carrier, but I'd feel much more comfortable at 800.
