as to #1.
then it really is adding or subtracting the bearing from your current heading. i've been playing around with it and conclude that bearings from 0-180 degress you add, from 181 to 360 you subtract.
for example: i'm heading 299 degrees and get a hearing heading at 347. i'd subtract 347 from 360, which is 13 and subtract that from 299, which is 286. so my new heading would be 286. or you can do the long math: 299 plus 347 = 646 minus 360 = 286.
another: i'm heading 137 degress and get a hearing heading 179. if i add 179 to 137 i get 316 and that's my new heading.
once the quick math is done, i change my course on the compass and voila, i'm done.
quicker method is yes, the periscope but i like my math thing better.
once i realized the hydrophone north/south was likened to my uboat, it all became crystal clear, well kinda.
anyway, thanks to all who replied, it now makes sense.
cheers!
frank