There are a lot of people fishing there. All day. In summer they gather a little bit further where is quiet.
But it is not a place for astrophotography. From one side is the port pf Piraeus which is (was) very busy always and from the other side is the commercial harbour of COSCO which is I think the 2nd or 3rd largest in Europe in Ship trade volumes. So there is lots of light population, plus the city of Piraeus and Athens.
I thought some places by the sea could be great for astronomy. Anyway, hope you had great Christmas.