Several years ago I discovered I had a relative who had served on board the HMS Tonnant at Trafalgar - a discovery which led me to learn as much as I could about the battle.
For anyone who wants to get a sense of what it was really like I would recommend Roy Adkins' book "Nelson's Trafalgar". It deals in great detail the living conditions, the diet, hygiene, discipline and health of the Royal Navy in 1805.
As alanabit says: "it must have been a pretty horrible experience for all those who took part in it". You are right, alanabit. It was a squalid, brutal and terrifying experience - as war usually is.