What is the function of a "swab" on a ship?

The function of a "swab" on a ship is that of a cleaning tool, specifically a mop. It is used primarily for maintaining the cleanliness of the decks and other areas on the ship. Swabs are essential in naval operations to uphold hygiene standards, prevent slips and falls, and contribute to the overall safety and operational effectiveness of the vessel. By having clean surfaces, crew members can work more efficiently and safely, which is vital in the high-pressure environment of a ship.

The other options refer to functions that do not align with the primary usage of a swab. Emergency signals are typically communicated through flags, lights, or sound signals. Tools for repairing equipment would include items like wrenches and screwdrivers, which are not designated as swabs. Communication on a ship is conducted through radios and other devices, not through a swab. Hence, the clarity of the role that a swab plays in ship maintenance underscores why it is accurately identified as a mop.