🔍 Key Concepts

• Potable water tanks are used for storing drinking water for crew and passengers • Vent lines must allow airflow in and out of the tank as water level changes • Consider what hazards or contamination could enter through an open vent on deck

💭 Think About

• Think about what you are trying to protect in a potable (drinking) water system: is the main concern pressure, safety, or cleanliness? • Which option directly relates to keeping the water safe for humans to drink? • Ask yourself what can easily pass through an unscreened opening on a ship and end up contaminating a water tank.

✅ Before You Answer

• Verify which answer choice most directly protects health and sanitation of the drinking water • Check whether the function of a vent screen is to block solid things (like pests or debris) or to treat the air itself • Eliminate any choice that mainly applies to fuel or cargo tanks rather than drinking water tanks