Advise passengers to keep cabin lights off or use red filtered lights. Do not blind another boater with your searchlight. Raise your all round stern light high enough and shield it underneath so it does not blind you when you look aft. Keep your speed down. It is difficult to judge speed, distance and type of vessel in the dark.
Depth perception is very different under low light conditions.
Carelessness, inexperience, overloading and failure to maintain a proper lookout are all magnified in limited visibility. Small, open, less stable motorboats with low freeboard are susceptible to capsizing. It is foolish and dangerous to add the effects of alcohol to the day's exposure of sun, fatigue, wind and waves. Know your boat lights and land lights in the area in which you go boating. It pays to review local charts and light lists often.