Having nighttime lighting on your Houseboat is a valuable convenience. Subdued lighting in a sheltered cove will not cause any disruption to other boat users in the area. The situation is different if you are positioned near a busy waterway. Here you will have to comply with regulations (https://www.boatus.org/study-guide/navigation/lights/) and also ensure that your, shall we say, recreational lighting cannot be confused with regulation lighting. Having bright lights tied up in a marina may interfere with other guests in the marina, and appropriate consideration should be given to neighboring boats.