Final answer:
The acceptable visual distress signal for night use only is a red flare or an electronic distress signal light.
Step-by-step explanation:
The visual distress signal that is acceptable for night use only is a red flare. Flares are commonly used as a distress signal to indicate an emergency and attract attention in case of an accident or danger on board a boat. The red flare is designed specifically for nighttime use and can be seen from a distance, making it an effective signal in low light conditions.
Another option for a visual distress signal acceptable for nighttime use is an electronic distress signal light. These lights are compact and lightweight, and they emit a bright, flashing light that is easily visible at night. They are typically powered by batteries and have a long shelf life, making them a practical choice for boating emergencies.
It's important to note that the choice of visual distress signal may vary depending on the country or region, as different regulations and requirements may exist. It is always essential to consult local boating authorities or guidelines to ensure compliance with safety regulations.