Final answer:
When a fishing vessel is trawling while making way, it is required to display white lights visible all around the horizon and specific shapes during the day, such as two black balls or a diamond shape, to indicate their activities.
Step-by-step explanation:
When a fishing vessel is trawling while making way, it is required to display certain lights and shapes to indicate its activities to other vessels. Typically, a fishing vessel trawling will display white lights that are visible all around the horizon. These may include fixed white lights or flashing white lights depending on the size and type of vessel. In addition to lights, a fishing vessel trawling will display shapes during the day. The shapes may include two black balls vertically arranged, one above the other, or a diamond shape, to indicate that the vessel is engaged in trawling. These lights and shapes help other vessels to identify and avoid the fishing vessel, ensuring the safety of all involved.