Had the same problem on my last patrol. Very difficult to see ships due to monitor reflections....had to ask WO for range, and bearings until I could see target myself.
Sometimes, however, watch is blind as a bat!! I played a homemade scenario once on a IXC, had a steamer bearing down on me..could not have been more than 1km away on a clear moonlit night...
watch did not see him...only by my lucky coincidence I happened to be on the bridge at the time and out of TC called full left rudder to avoid a collision....finally the watch calls out:" Shift geshikted".... :hmm: