Master (i.e Captain) is in charge of the overall navigation of the ship and the journey and safety of the crew.
Ship Surgeon (arguably equally or more important than captain, ensures health and well-being of those on ship and also in charge of some discipline).
First-Fifth Mates all responsible for helping the captain and navigating the ship. Also rank above and occasionally direct boatswain and able-bodied and ordinary seamen.
The Boatswain (effectively ‘killed’ by steamers, used to be known as the “bucko” mate). Highest rank beneath officers, answers to the first mate and is the “foreman of the ship” (foc’sle and gloryhole 23). Is responsible for giving directions to able-bodied and ordinary seamen.
The Able Bodied Seaman (difficultly defined, may be promoted to 1 of 3 quartermasters). The Able Bodied seaman must have passed a health examination and a skill examination determining if he understands nautical terms and how to perform common tasks on board the ship.
Cuddy Servant (waits at dinner, does galleywork: washes dishes, mops floors, sets tables, cleans leftovers, may help cook).
Captain’s Servant (status of boy around 12 years of age entering ship before becoming midshipman).
The deck boy (3 years to AB, 1 year to become OS). The deck boy had to do relatively simple tasks like clean the dishes or mop the floors and would usually be challenged by the boatswain to learn more difficult tasks such as those required by ordinary and able-bodied seamen.
Fiddler. The fiddler would most typically play music aboard the ship on his fiddle, and interestingly did so during times such as when the sailors were heaving an anchor. It would seem that the fiddler served both an entertainment and synchronizing function on board the ship, especially as recounted by Walter Downie in Reminiscences of a Blackwall Midshipman.