Which option best describes 'engaged in fishing'?

Answer: C — Using fishing apparatus which restricts maneuverability

In the rules, a vessel is considered “engaged in fishing” when she is actively using fishing gear that limits her ability to maneuver. This restriction in maneuverability is the defining feature. The best description matches that exactly: a vessel using fishing apparatus which restricts maneuverability. The other descriptions don’t fit this specific situation. Using fishing gear that does not restrict maneuverability means she isn’t engaged in fishing under the rule’s definition. Being restricted in her ability to maneuver describes a different status or condition, not the act of fishing itself. A power-driven vessel is a classification by propulsion, not about whether she’s engaged in fishing.