🔍 Key Concepts

• Watertight doors are part of a unit’s subdivision and damage-control system • How and when emergency equipment must be operated or exercised on a Mobile Offshore Drilling Unit (MODU) • Difference between routine drills and conditions affecting watertight integrity while underway or on location

💭 Think About

• Ask yourself: in which situation is it most critical to maintain or test the MODU’s watertight integrity—only during practice drills, on a calendar schedule, or in an actual change of operating/sea condition? • Which option best reflects a condition where flooding risk or hull exposure to the sea may change significantly? • Consider whether watertight doors are mainly for personnel training, for time-based maintenance, or for protecting the unit when its stability and sea-keeping are more at risk.

✅ Before You Answer

• Identify which choice involves a change in ship/rig condition relative to the sea rather than just a scheduled drill • Verify in current regulations/guidance how MODU watertight doors relate to damage stability and subdivision requirements • Check which answer describes a situation where improper operation of watertight doors could have an immediate stability and flooding consequence