Wire Submarine Radar

I’ve been working to design a realistic submarine in Gmod, which will call for a simulated sonar system that reveals terrain and targets; basically, I require a means of underwater navigation and detection, sans visual, preferably a simple system based on a ranger that translates data to an oscilloscope.

http://www.dkimages.com/discover/previews/968/90073533.JPG

However, being the wire-illiterate, comically-bad-at-math fool I am, I am utterly clueless as to how to make such a system! Would anyone knowledgeable enough on the subject be so kind as to enlighten me in this matter?

Lots of wire, math and expression 2 coding.

The simplest way would be to put rangers where the image you posted indicates and have them display the distance they scan to screens.
That way you can see when you are about to crash into a wall because the distance gets very small.

…none of which I am the faintest bit proficient in.

I’m well aware of the system by which it would function- my quarrel is how to make it work, and in addition, how to display that data on an Oscilloscope.