Final answer:
The lights for a towed vessel alongside include navigation side lights, a stern light, and an all-round white light, with a diamond shape displayed by day as required by COLREGs.
Step-by-step explanation:
The lights and shapes required for a vessel when it is towed alongside another are specific navigation lights that indicate the vessel's status to others on the water during the night and times of reduced visibility. The International Regulations for Preventing Collisions at Sea (COLREGs) outline these requirements, generally including a set of side lights (green on starboard and red on port), a stern light (white light at the vessel's stern), and an all-round white light representing the towing vessel at the stern of the towed vessel. By day, a diamond shape is displayed to indicate a vessel being towed alongside.