Question 4699 Deck General

The correct answer is A) columns and upper structure. On a semisubmersible MODU (Mobile Offshore Drilling Unit), the reserve buoyancy is increased by the presence of void spaces above the waterline in the columns and upper structure. This is because the columns and upper structure of a semisubmersible MODU are designed to provide additional buoyancy and stability, which is crucial for maintaining the platform's stability and safety during operations. The other answer choices are incorrect because the submerged hulls (B), submerged connecting structures (C), and quarters (D) do not directly contribute to the reserve buoyancy of a semisubmersible MODU. The reserve buoyancy is primarily provided by the void spaces in the abovewater portions of the structure, specifically the columns and upper structure.