Fleet navigation and nuke defense (Fearless Blue)

Let us use co-ordinates to move fleets...
nuke defense, documentation is a little out of date. Defense against nuke subs goes on about frigates...since there are no frigates in the game!! This need to be updated. I would like to know how/if defensive destroyers actually defend against sub attack.

co-ordinate , i like that idea , by the way ,i think there is a frigate missile thing now.