I'm extremely tentatively eye-ing a CDT thru hike within the next say 3-5 years. I live in the mid-atlantic, the world of blazed and defined trails. I can read a topo map, know the very basics of a compass, and typically my useage of those skills amounts to trying to identify adjacent peaks from whatever trail vista I'm at. I've not had the need or made the opportunity to attempt true cross-country navigation for any significant stretch. I did complete an AT thru hike in 2016 and have backpacked extensively in the mid-atlantic, but none of this requires appreciable navigation skills.
I was looking for training or courses on navigation that would get me on track to be able to handle something like the CDT. Googling "backcountry navigation course", you seem to get 4-hour workshops at REI, a number of bushcraft guys and marines pitching navigation as a component of an overall "survival" type training, and a handful of inactive orienteering clubs. I acknowledge that this is a skill one develops through experience but by the same token I feel you do need a qualified, systematic introduction to these techniques.
Any organizations or individuals that anyone can recommend that offers instruction suitable for where I'm trying to get?