Finding Range

[Klund]

I'v been using 100% realism settings in my new career and everything has been going reasonably well. The notebook approach to finding the range of the target has never really worked for me but because I usually get in close (500-700) then I just set it to what I think the distance is.

In 1942 now and finding it much more difficult to get in close and finding myself taking shots much further away where range has become a factor and my approach to it not working. What is then the best way to determine the range of the target? If the answer is putting the periscope line on the waterline and the notebook range finder tool on the top mast then I'm afraid it is never accurate at all for me, when I know the range is 500-700 and I use the notebook approach correctly it gives me a range of 1500 or so.