Mercantile Navy List - info on ship masters and mates
 

I've just discovered that Google Books has several mid-19th century editions of the Mercantile Navy List, which lists everyone who was qualified as a Master or Mate in the merchant navy. I'm still finding my way around them, but each edition has an alphabetical list of people and also a list showing what grade they had reached, which examining board, date qualified, etc. Definitely worth looking at if any of your ancestors were ship captains or mates.

Thanks for the heads up. Always looking for something on my Edward Sheldrick... lol