Help with RAOBF dis. My measurements are off.

This is how it works for me.

[nazaka]

Try doing the same thing with a Large Liner.

You'll never get the measurement right, even with your method.
The mast is off by almost 4m.

[Pisces]

Originally Posted by Alpheratz

This is how it works for me.

Are you sure you are interpreting the scale correct? Remove the recognition manual. Is there another marking "10" on the opposite side of the horizontal centerline? Or does the scale start counting from the bottom?

[Markus Witt]

Alpheratz calculation is correct. Personally I always have a sliderule standby for quick and easy range calculations. In this example I get a range of 2850 meters, see attached. Sliderule is also handy to calculate in advance the number of crads you need if you want to fire at a certain range.

In this example actual range is (29.9) / (4.2 / 4) = 2848 m.

Originally Posted by Pisces

Are you sure you are interpreting the scale correct? Remove the recognition manual. Is there another marking "10" on the opposite side of the horizontal centerline? Or does the scale start counting from the bottom?

Yes, I am sure. I checked the graduation of the radian scale on lighthouses as well. Previously, I carefully determined the height (70m) and the location of the lighthouses using RAOBF before posting the tutorial video (SH5 School of Navigation. Level 1). I also tested my centiradian table on 5 types of ships: only in one case, probably due to an incorrect mast height in the recognition manual, there were erroneous readings. In all other cases, the readings are consistent with each other and with the RAOBF results. Here's an example with a lighthouse. U-boat is located in Narvik at a distance of 1000 meters from the lighthouse.