I've lost count how many I've seen. Fair enough if you think it is done better elsewhere. Perhaps you could give a breakdown of exactly what you think should be in a good Nav class?
I'll tell you how I do it ... and I don't teach it as a separate specialty, it's part of my AOW curriculum.
First, the classwork ... we start by talking about the compass ... how it works, and how to use it. We do some dryland drills just picking a series of headings and having the students "walk" the course, following the compass. That familiarizes them with the equipment. Then we talk about the methods ... using the compass, using visual cues such as natural landmarks, current direction, and bottom topography. Then we talk about "mental mapping" techniques ... using depth, direction and distance to build a series of vectors that you string end-to-end to create a map in your head of where you are relative to where you started.
The navigation portion of the class involves two dives ... but these dives may be repeated as necessary. The first involves a series of flags planted on the bottom. The first flag is located at the bottom of the downline, and it contains a heading to the next flag, which contains a heading to the next flag, etc. There are a total of six flags ... the headings are randomized sufficient to not be a recognizeable pattern. The final one says, simply ... HOME. When you reach that point, the student's job is to make their way back to the downline where they started. They can do this either by reversing course (which is very inefficient) or ... having built that "mental map" ... by taking a direct route to where they think the downline is located. Many make it on the first try ... some need two or even three attempts. I have yet to have one need more than that.
Second dive is a mid-water navigation dive ... we're far enough off the bottom so that the students have no visual reference ... the entire dive is done at a constant depth (20 feet). The students are given a series of patterns ... square and triangular routes ... with headings and timed legs. One student gets the compass, the other gets the depth gauge and bottom timer. The objective is to complete the pattern by working together to maintain both a constant heading and a constant depth ... and a successful conclusion will bring them back to the downline. This dive is about way more than navigation, as it also teaches the importance of maintaining awareness of your surroundings as well as the notion that a good buddy team can accomplish more by working together. We do a minimum of three patterns ... but sometimes this dive requires several attempts to do it successfully. By the time the student achieves the objective, diving with visual references seems easy by comparison.
The majority of my students tell me that the first dive is the most fun dive of the class, while the second one is the most difficult ... but I guarantee you that by the time they're done, they have a pretty good idea how to find their way around down there ...
... Bob (Grateful Diver)
