🔍 Key Concepts

• Understand what longitudinal distance between draft marks means (it is measured along the vessel, not vertically). • Recall where forward and aft draft marks are typically located on a vessel or MODU like DEEP DRILLER (near perpendiculars). • Relate the distance between draft marks to the vessel’s length between perpendiculars (LBP) or overall length, as given in vessel particulars or exam tables.

💭 Think About

• Look at the DEEP DRILLER data sheet or stability booklet used in the exam materials: what are the positions (stations) of the forward and aft draft marks? • Convert any given positions into a simple distance along the length (aft to forward) and compare that with the answer choices. • Ask yourself: is the distance between draft marks usually close to the vessel’s full length, or somewhat less than it? Which options are realistic for a large offshore unit?

✅ Before You Answer

• Verify the units and formatting of the answers (feet and inches) and be sure any calculation you do is in the same units. • Confirm from the data sheet that you are using the correct pair of draft marks (forward vs aft, port or starboard as applicable). • Double-check subtraction of station positions (fore and aft) to avoid simple arithmetic errors before matching your result to the choices.