There are two professional paths, deck or engine.
Deck officers are responsible for the navigation of the ship and loading and unloading of cargo.
Engineering officers are responsible for the operation and maintenance of machinery aboard the ship. Officers may work on the large ore boats that run the Great Lakes, on seagoing vessels operating in the Great Lakes, or onboard ships of the U.S. saltwater fleet. Merchant Marine Read a profile of Velda Hammerbacher, a third mate in charge of navigation, loading and unloading operation during watch. Post a question or comment about this career in our Great Lakes Careers Discussion Forum Great Lakes Maritime Academy Site provides a good overview of different careers related to the merchant marine and preparation needed for those careers.