It is a visual reference as to where the clear water is. Otherwise it is difficult to know how close to the surface the diver is.
Olympic was first
There was no Olympic Games outside of Greece before the first one was recorded.
Before 1896, the year of the first Olympics.
776 before Jesus-chirst
Athens in Greece
The first Winter Olympic Games held in Russia were in Sochi in 2014.
So you don't make a mistake.
No this is the first time, a link is below for host countries.
They have never host the Olympic before. 2016 will be their first time.
2008 beijing. It has always been in Europe before that.
what is the shape of the first olympic stadiam