I recently finished a printable is-was for SH4 that can be had in this topic here:
http://www.subsim.com/radioroom/showthread.php?t=106923, and in the way I learnt a lot about this simple but sophisticated tools. I have seen several designs, and I am thinking of using my templates -it's just a little work now that the most time consuming part is done- to create a wiz-wheel specifically designed for SH3, i.e. with meters as measuring unit and with Kriegsmarine emblems and such stuff. The idea is to be able to get target's course and speed from two different range measurements at different time intervals -no matter which interval, does not need to be three minutes, and can be any other you prefer- and make targeting at 100% realism (No God eye) much easier.
I would start the task if there is interest in it, and also can do it to be used in the backside of Etchasketch's AOB finder if you like to.
So if you want one, post your request here. If enough people demand it, I will do it.