Question 60 ONC05 - Master or Mate of LT 200 GRT

The Correct Answer is B **Why option B ("Moving a weight forward") is correct:** Trim is defined as the difference between the draft forward and the draft aft. Moving a weight forward (or aft) changes the vessel's longitudinal center of gravity (LCG). This shift in the LCG creates a moment (a force multiplied by a distance) around the vessel's tipping center (or center of flotation), which causes the vessel to pivot longitudinally. Moving a weight forward will cause the vessel to trim down by the bow (increase the forward draft relative to the aft draft), thus affecting the vessel's trim. **Why the other options are incorrect:** * **A) Adding weight at the tipping center:** The tipping center (or center of flotation, $C_f$) is the point about which the vessel pivots longitudinally when changing trim. Adding or removing weight directly over this point only changes the overall displacement (draft) of the vessel, but creates no longitudinal moment. Therefore, it changes the mean draft but does not affect the trim. * **C) Moving high weights lower:** Moving weights vertically affects the vessel's stability (specifically, the metacenter $GM$) and changes the vertical center of gravity ($VCG$). It does not create a longitudinal moment and therefore does not change the vessel's trim (the difference between forward and aft draft). * **D) Removing weight at the tipping center:** Similar to option A, removing weight directly at the tipping center only changes the mean draft (displacement). Since no longitudinal moment is created around the tipping center, the difference between the forward and aft drafts (the trim) remains unchanged.