As a management level engineering officer on a motor vessel equipped with engines capable of burning both high sulfur content residual fuels and low sulfur content distillate fuels, on departure from a US port, when would you plan for the fuel changeover be accomplished?

Correct Answer: Option B — When leaving the SOx emission control area set by local authorities.

MARPOL Annex VI and local regulations mandate fuel changeovers when exiting designated Emission Control Areas (ECAs). Engineering officers must plan the transition to low-sulfur fuel to ensure compliance with SOx emission limits before entering or upon leaving these regulated zones, regardless of the vessel's distance from the coastline.