The holiday boat parades begin in two weeks, so as you plan the decorations, remember to keep safety in the forefront of your mind, with the utmost importance being that the skipper must be able to see.
A high percentage of the collisions or near misses I have witnessed are due to two primary things: skippers' lack of visibility all around the vessel and the skipper simply not paying attention to the duties at hand. Should the skipper's view be limited, have someone be a lookout to watch the blind areas. On some larger boats I skipper at times, I have had a few lookouts helping me avoid any problem situations.
Over the years, I have seen some very hazardously decorated boats, and on a couple of occasions, I have been zapped touching the metal railings from a wet extension cord grounding there. All of the exterior electrical cords should be for use outdoors with all the connections wrapped with electrical tape to prevent grounding. You will experience dew point during the parades and, in some years, it has rained, so plan ahead now to prevent electrical hazards.
The decorations cannot obstruct or prevent the deployment of any safety devices aboard your vessel, including ring buoys, life rafts, life jackets and fire extinguishers. For example, do not wrap a string of lights around your throwable ring buoy, making that lifesaving device useless if someone falls overboard.
Furthermore, the decorations cannot interfere with the vessel's navigational lights. An easy solution is to enhance your navigational lights by putting red light bulbs in by the port light and green light bulbs in by the starboard light. Technically, unless you are in a sanctioned parade route, it is not proper to display your Christmas lights if the lights distract from the navigational lights. However, the Harbor Patrol and the Coast Guard are using their discretion in enforcing this regulation during December, so cruise safely.