Mark:
the only Latin 'tag' that I can recall Nelson using was 'Post nubila, Phoebus' - 'after the clouds, sunshine' - when he finally got a ship after his five years on the beach.
He would almost certainly have learned Latin at school. The Classics were the basis of the 18th century school curriculum, though other subjects were added. The introduction to this paper outlines what was sometimes taught in addition to the classical 'core'.
http://www.eric.ed.gov/ERICWebPortal/cu ... o=ED054038
If Nelson's resistance to French is anything to go by, he probably didn't excel at Latin or Greek either. His arithmetic was a bit wobbly, his grammar sometimes likewise, his recollection of Shakespeare fragmented and inaccurate. What WAS Nelson good at in the academic field? It is a perennial problem for educationists, and I speak from experience here: you encounter students who are, like Nelson, articulate, bright, responsive, energetic, socially well-adjusted and usually incredibly well-informed, but they don't have an academic bent and can become directionless. I often suggested that my pupils might consider the armed forces, and several of them did indeed find purpose and satisfaction in that route.