🔍 Key Concepts

• Longitudinal moment is found by multiplying the weight by its longitudinal arm/LCG (longitudinal center of gravity) from the reference point • Tank data (like the #1 drill water tank’s longitudinal position/LCG relative to the vessel’s FP or AP) is taken from the COASTAL DRILLER hydrostatic or tank capacity data • Be careful with units: weight in kips and arm in feet give a moment in ft-kips

💭 Think About

• What is the longitudinal distance (arm) for the #1 drill water tank given in the COASTAL DRILLER’s data, and from what reference (FP or AP) is it measured? • Once you have the arm, what simple calculation do you perform using the 379.97 kips and that arm to get the longitudinal moment? • After you compute the moment, how close is your number to each of the answer choices, and do you need to consider any rounding from the tank table values?

✅ Before You Answer

• Confirm the correct longitudinal arm/LCG value for #1 drill water tank from the stability/tank data (do not guess) • Verify that the weight is in kips and the arm is in feet, so the resulting unit is ft-kips • Recalculate the multiplication carefully and check for rounding differences that might shift the answer by about 10 ft-kips