🔍 Key Concepts

• 46 CFR requirements for inspection and certification of offshore drilling units • Difference between annual inspections and dry-docking intervals • How often major structural and underwater hull inspections are normally required for large vessels and MODUs (Mobile Offshore Drilling Units)

💭 Think About

• Think about why dry-docking is required and what parts of the unit must be inspected while out of the water. • Compare typical inspection intervals for regular vessels with those for specialized units like offshore drilling rigs. • Ask yourself: would regulations require very frequent dry-docking for such large, complex units, or a longer, planned interval?

✅ Before You Answer

• Verify the specific subpart of 46 CFR that covers mobile/offshore drilling unit inspection and dry-docking. • Check whether the rule says "at least once during every" followed by a multi-year or single-year period. • Confirm that this requirement is different from annual inspection or COI (Certificate of Inspection) renewal intervals.