Training, Other Qualifications, and Advancement: Entry, training, and experience requirements for many water transportation occupations are established and regulated by the U.S. Coast Guard. As of April 15, 2009, mariners on board most ships have to obtain two credentials, a Transportation Worker Identification Credential (TWIC) and a Merchant Mariner Credential (MMC).

Education and training: Entry-level workers are classified as ordinary seamen or deckhands. Workers take some basic training, lasting a few days, in areas such as first aid and firefighting.

There are two paths of education and training for a deck officer or an engineer: applicants must either accumulate thousands of hours of experience while working as a deckhand, or graduate from one of seven merchant marine academies in the United States. In both cases, applicants must pass a written examination. It is difficult to pass the examination without substantial formal schooling or independent study. The academies offer a 4-year academic program leading to a bachelor-of-science degree, a MMC endorsement (issued only by the Coast Guard) as a third mate (deck officer) or third assistant engineer (engineering officer), and, if the person chooses, a commission as ensign in the U.S. Naval Reserve, Merchant Marine Reserve, or Coast Guard Reserve. With experience and additional training, third officers may qualify for higher rank. Generally officers on deep water vessels are academy graduates and those in supply boats, inland waterways, and rivers rose to their positions through years of experience.

Harbor pilot training usually consists of an extended apprenticeship with a towing company or a harbor pilots' association. Entrants may be able seamen or licensed officers.

In recent years, to generate interest in the maritime industry, 18 high schools have been designated “maritime high schools” with a curriculum created by the U.S. Maritime Administration. Graduation from one of these schools can help one’s entry in the academies or with jobs elsewhere in the industry.

Licensure: All mariners that are required to obtain Coast Guard credentials are required to obtain a TWIC from the U.S. Department of Homeland Security. This credential states that you are a U.S. citizen or a permanent resident and have passed a security screening.

In addition, with few exceptions, the Coast Guard requires that mariners applying for a credential after April 15, 2009, obtain a MMC. Entry level seamen or deckhands on vessels operating in harbors or on rivers or other waterways do not need a MMC. The MMC replaces the Merchant Mariner Document, the license, and Standards of Training, Certification, and Watchkeeping for Seafarers endorsement. The MMC incorporates the licenses into the credential, which varies by occupational specialty, type of vessel, and by body of water (river, inland waterway, Great Lakes, and oceans). Requirements for the credential increase as the skill level of the occupational specialty and the size of the vessel increase and applicants must pass a test in order qualify. Applicants for the credential must also pass a drug screen, take a medical exam, and meet the minimum age requirements. For more information on credentialing requirements see the Coast Guard's Web site listed in the sources of additional information.

Radio operators are licensed by the Federal Communications Commission.

Other qualifications: Most positions require excellent health, good vision, and color perception. Good general physical condition is needed because many jobs require the ability to lift heavy objects, withstand heat and cold, stand or stoop for long periods of time, dexterity to maneuver through tight spaces, and good balance on uneven and wet surfaces and in rough water.

Advancement: Experience and passing exams are required to advance. Deckhands who wish to advance must decide whether they want to work in the wheelhouse or the engine room. They will then assist the engineers or deck officers. With experience, assistant engineers and deck officers can advance to become chief engineers or captains. On smaller boats, such as tugs, a captain may choose to become self-employed by buying a boat and working as an owner-operator.