BOTH INTERNATIONAL & INLAND The white masthead light required for a power-driven vessel under the Rules is visible over how many degrees of the horizon?

Correct Answer: Option C — 225.0°

Under Inland Navigation Rules, for the condition where 'The white masthead light required for a power-driven vessel under the Rules is visible over how many degrees of the horizon', the correct requirement is: '225.0°'. This standard ensures clear navigational intent and collision avoidance.