Master mariners can also be referred to as ship captains, marine captains, sailing masters, or nautical masters. These terms all describe experienced seafarers who have achieved the highest level of certification in the maritime industry. A master mariner possesses the skill and knowledge necessary to command a large commercial vessel and navigate through complex waterways. They are responsible for ensuring the safety of passengers, crew, and cargo during a voyage. These synonyms are often used interchangeably and emphasize the leadership role of a master mariner in the maritime industry.