I don't think it was ever the case that everybody on board was taught astronav. It's very much a thing that's taught to the people who need to be able to calcul

I don't think it was ever the case that everybody on board was taught astronav. It's very much a thing that's taught to the people who need to be able to calculate where the ship is. That's about 4 or 5 people on a typical warship, and then you can add to that pool the number of people who did hold a job that required the skill but have since been promoted.