If you are handy with scissors, cardboard and laminating foil you can also make a hardcopy version of it. Then you can use it in any station and at any time you want. Or with any game that uses km to measure distance.
http://www.subsim.com/radioroom/down...do=file&id=321
There are more 4 bearing methods described here on the forum, under both the SH3, 4 and 5 section. Names of the thread-starters are Mittelwaechter, Nefelodam, Kuikeg, jerm138 and a few I can't recall right now.
Back in the early days I found a neat simple trick on the RAOBF wheel to calculate the intercept lead angle when left without other tools. I'm not a 100% sure it works on the latest scales OLC made in his GUI, or those made by others in their GUIs, but can't imagine why it would not work mathematically. (caveat: I had a migraine headache this morning and am recovering from the flu the past days. YMMV, check the numbers with the intercept formula)
http://www.subsim.com/radioroom/show...428#post694428