So, does anyone know of any good sources, fictional or factual, contemporary or (at least mildly well-researched) modern, for what it might be like for my character, a navigator's apprentice (more or less) on a smallish British merchant vessel in the 1800s, give or take half a century? If there's nothing that specific, anything about any small to medium merchant vessel or the like from about that era, or anything about being a navigator on any vessel from about that era, would be helpful. Specifically military stuff would be less than entirely useful if it doesn't cover navigation much, but privateer or pirate stuff might be helpful.
In terms of non-contemporary fiction, it doesn't need to be super, super, super accurate, just not, eg, Pirates of the Caribbean-level flights of fancy.
Bonus points if it's free. Super super bonus points if it's on Librivox (or some other legal free audio-book source), so I can listen to it in the car.
Searches: poked about a bit randomly with search terms like "1800 British merchant ship", also looked at the Wikipedia page for "nautical fiction". Kinda wasn't sure how to approach this.
edit to clarify: I'm aiming for anything set/about between ~1750 and ~1850, but preferably towards the center of that range. So, no steam ships.