What is the correct immediate response to a confirmed drift-off (power/thrust loss), and how does it differ from the drive-off response?

A. The response is identical to a drive-off — isolate the suspect thruster first in both cases

B. Immediately go to emergency anchor in all drift-off situations

C. Apply maximum counter-thrust immediately in joystick mode

D. Alert the platform/structure immediately and assess drift trajectory; attempt to restore power or use emergency generator; anchor is a last resort — the vessel is not being actively driven so there is more time to assess before intervening

A. A drive-off occurs during manual joystick mode; a drift-off only occurs in DP auto mode

B. A drift-off is always slower than a drive-off

C. A drive-off occurs when a thruster malfunction or DP system error actively propels the vessel away from position against the operator's intent; a drift-off occurs when power or thrust is lost and the vessel moves passively under environmental forces

D. They are two terms for the same event — the vessel leaves its position in both cases

A. Because drive-offs only occur in bad weather when the vessel is already at risk

B. Because a drift-off always results in a controlled shutdown, whereas a drive-off does not

C. Because thruster power is being applied in the wrong direction, accelerating the vessel toward (or away from) the structure — the vessel gains speed rapidly and the DPO has very little time to stop it before impact

D. Because drift-offs are automatically detected by the DP system and corrected; drive-offs are not