just one paragraph was added, on the subject of the target course and angle finder tool, that the bearings given by the course solver are always read as true bearings.
the tutorial is finished now.
thanks rosie,

i think you asked me, what if a sound contact is already with in the listening range of the hydrophones.
i just started working on that tonight, and i think i might have something, in a general sense of range to target. my goal is precision, but ill settle for general range at this moment. im looking at two things, sound cones and bearing width, and using the hydrophone ambient noise, as a comparator, in relation to the volume of the screw sounds.
ill write about these subjects tomorrow night, but here is a picture of the sonar cone width, and the ranges the target could be at, at a certain width of the hydrophone sound cone.