Which of the following actions is NOT permissible for a vessel navigated under power while fishing?

The action of impeding the passage of a sailing vessel is not permissible for a vessel navigated under power while fishing because it compromises navigational safety and violates the Rules of the Road. Under international maritime law, specifically the COLREGs (International Regulations for Preventing Collisions at Sea), all vessels must maintain safe passage and avoid impeding the safe and efficient navigation of other vessels, especially those engaging in sail.

When a powered vessel is fishing, it still must adhere to the rules that apply to all vessels. This includes respecting the rights of sailing vessels that may have limited maneuverability compared to powered vessels. Thus, actively impeding a sailing vessel's passage would be considered a failure to comply with these regulations.

In contrast, using trolling lines, keeping a lookout for other vessels, and sounding fog signals when necessary are all permissible and responsible actions for a vessel under power that is also engaged in fishing. These actions contribute to safety on the water, ensuring that the vessel is aware of its surroundings and ready to communicate effectively in conditions of reduced visibility.