Sorry for posting a problem
Not sure if your still wanting to of any sonar glitches at all but have just encountered a Large Modern Tanker that couldn't be picked up on sonar even at 700 yards when crossing in front of me.
Date was 6 June 1942, grid square 143E 3S just north of Dagua, New Guinea.
Was at periscope depth in an S class, 1 knot.
RFB is so good, have had an enjoyable hour chasing down another tanker in my pig boat (both with Davy Jones now
) thanks again for all your hard work.
Steve