Personally, I like your marina quite a bit. Most of the ones on the West Coast have just one entrance, as do any marinas where the ocean is rough. Speaking as a person who just spent 40 days at sea all along the Alaskan coast, every harbor I entered had a reasonably tall light pole at the entrance. This will be a white light, and its distinct from the navigational buoy lights. It is to mark out the marina and harbor entrances in the case of heavy weather or heavy fog. Even at Dutch Harbor out in the Aleutians, there was that light pole on the end of the spit. Also, any harbor than handles ships over 35 feet typically is required to have navigational buoys as well - usually both the red and the green to mark the two sides of the passages.