I have never put a flag up on a boat but I put it on my car. I used a solar flag pole light. If you are interested I ordered it from here https://www.amazon.com/Flagpole-Energy-Battery-Illumunation-Vont/dp/B00YBDA7DC/. The main reason I chose this one is that it has a good illumination, automatic daylight sensor and, what is important, it is installed in 1 minute without any tools. Also, what I mentioned, solar flag pole light is very bright and it has a long lasting batteries. I don’t know it will help you or not, but you should definitely check this thing out.