If one is trying to get into a narrow entrance on a lee shore at night there is nothing handier than a reflector cemented into the rocks as a positive identification point. a galvanized carriage bolt thru the centre lasts a long time , an SS one lasts a lifetime. They can mark both sides of an entrance, or one side, or be put in line to show the safe channel. They make entering your favorite anchorages at night much easier and safer.
Reflectors can be cut from old aluminiunm traffic signs bought by the pound in scrapyards. The writing on them can be easily washed off with laquer thinner , leaving the reflector surface behind. They also are good for locating mooring buoys,and if you put them at various locations on your boat ,a boat enteriing at night with a spotlight will see your boat light up like an xmas tree. They also make dingies that go drifting at night much easier to find.
Adding our own aids to Navigation makes big brother less relevant, a good thing in the long run. I've found them extremely help full in my favorite anchorages.
Brent