The best procedure for long range cruise performance in the type VII is to set the speed to 8 - 9 knots.
This should yield the longest range and best fuel economy.
The best way to get an accurate measure of your remaining range is to set time compression to about 512x and ask the navigator to report the remaining range about every 2 or 3 seconds until you have 4 or 5 reports.
you can do the math by pencil and paper or
just guess at an average of the 4 or 5 numbers. this average is your best estimate.
usually his first estimate is in error by a large margin, so it is best to ask for 4 or 5.
If you are in any kind of rough sea, this will affect the reported range substantially.
hope this information helps!
