it's possible add marine navaid

For something to show up on an OSM map, two things are required. First the object in question has to be mapped, i.e. somebody has to mark it in an editor and add the appropriate "tags". Then, a rendering engine has to pick up the objects and say "oh, here's something tagged as an unlit green navaid, let me use this icon for it".

As far as marine navaids go, there is a tagging scheme for them (see the Wiki). They will not be rendered on the main map on openstreetmap.org because that map is not supposed to be a marine map; but check out OpenSeaMap as an example of a specialist map that renders these navaids. You can of course also install rendering software and create your own maps, for example if you want exactly the icons depicted in your question and are not happy with those chosen by OpenSeaMap. See the question How do I render my own maps for my web site?.

I've added a few buoys around the Clyde using the OpenSeaMap JOSM plugin, which I recommend for adding navaids, manually adding tags is tricky because there are so many of them to use.