Buoys come in many types. The chart uses standard symbols for these, though in reality, the actual buoy can vary between a small unlit plastic item to a massive granite tower. Here is a selection of buoys from around Europe.
Danish port hand buoy.
East Cardinal Buoy, Holland.
Isolated Danger Mark, Le Vieux Chien, L'Aber Benoit, Brittany.
South Cardinal Buoy, St Mawes, Falmouth.
Starboard Buoy, The Vilt, Falmouth
The infamous west cardinal at the Raz du Sein, Brittany.