First mate - Received orders from the captain and transmitted them to the crew. He was in charge of the setting and lowering of sails, all aspect of the rigging, and ship repairs. He was often hired directly by the owner of the vessel and could not be removed by the captain. He was responsible for keeping an accurate log book and commanded the larboard watch.
The Third Mate - only found on large vessels and chosen by the captain from among the most senior able seaman. In some cases, they were designated as bosuns, which were petty officers who were in charge of the crew.
Idlers: - specialized workmen who did not do the work of seaman or stand watch. Idlers commonly included the carpenter, the sailmaker, and the cook. Larger vessels might have a cooper, steward, armorer and other tradesmen. On smaller vessels, an idler could sign on as both an able bodied seaman and a carpenter, etc.. Cooks were never seamen and were usually older sailors with missing limbs unable to do normal seamen tasks.
Ordinary seamen - not quite at the level of an able seaman, the ordinary seaman was expected to 'hand, reef, and steer under normal weather conditions'. They did not have to be a competent helmsman but should be acquainted with all the running and standing rigging of the ship
Within the Able and Ordinary Seamen existed these titles
Sheet anchor men - worked on the forecastle handling the anchors, jibs and foreyards.
After-gang - working the aft deck these men dealt primarily with the mainsail and spanker and worked on the lines and haliyards
Waisters - worked in the ship's waist.. the center deck below the top deck
Holders - Worked in the hold
Clear as the bilge in the hold? It thought so!