The term 'Seaman Descriptor' is a job title in the maritime industry. It refers to a person who is responsible for the safe and efficient operation of a vessel. The term 'ABLE' is an acronym which stands for ABLE Seaman, which is a rank in the merchant navy. An ABLE Seaman is a qualified mariner who is ABLE to perform all duties related to the operation and handling of a ship. They are responsible for navigation, lookout duties, cargo operations, and other tasks as assigned by the captain.