A semisubmersible, 200 feet in length between draft marks with the LCF 10 feet aft of amidships, records the following drafts: Port Forward 64'-9"; Port Aft 68'-9"; Starboard Forward 59'-9"; and Starboard Aft 63'-9". What is the true mean draft?

Correct Answer: Option B — 64.45 feet

True mean draft requires correcting the average of port and starboard draft marks for trim and the longitudinal center of flotation (LCF) location. Using standard hydrostatics for semisubmersibles, averaging the four corner drafts and applying trim corrections yields 64.45 feet.