I'm curious because when we hear about someone like admiral Nelson rising to the top, we usually aren't given specific details re: how that happened. I'm assuming it involved a combination of a few of the following factors but would love to learn more:
I think an important clarification here is what side of the house are you asking about, or both?
The experience with a career of service and opportunity for promotion would be very different for a commissioned officer like Nelson than it was for one of his enlisted sailors. There are some overarching themes and types of ways to advance a career, but just as today the forces in the age of sail operated two separate HR Departments basically for Officers and Ratings.
I've answered similar questions a few times before. Let me know if you have any follow ups!