SUBSIM Radio Room Forums - Yet another question on plotting

After a long break I'm trying to play Silent Hunter again. Due to some problems with my old rig I couldn't try Operation Monsun two years ago and I'm more familiar with SHIII than with the Four. When I launched a partol in OM/OMEGU I realised that the 1WO no longer gave distances to the closest contact.
I play with Map Update disabled and try to stick to realistic procedures. Knowing that on U-boats they didn't have those supes-accurate gyroscopic GPS-calibrated DRTs they have today I always prefered to use relative plot instead of geographical one and solve on MoBo (I'd often run MoBo on my working netbook, so I can't update my position accurately even though I still didn't turn to celestial navigation) used as a maneuvering board. But now, without the report on the range and the target being too far for the stadimeter, I can only plot bearings and try to calculate his course and speed from the bearing change rate? I see the kind of procedure to use but I wander if there is no simpler way of doing it.
And then I stumbled in "Clear the Bridge" on a passage where the author referred to the maneuvering board as "old fashioned". This would mean that they didn't solve for a shot on the moboard as a routine, but then how did they do it if with celestial navigation they could not know their position with a precision of several metres?