Water colour of a coastal communication station

Among the many photos that have come into my possession from my late Mother, are a couple of small watercolours. The other one is a very simple seascape of the Entrance to the Pireaus. This one fascinates me. It is very precise. I would guess that it is from the beginning of the 20th century. The tall mast still has the rigging for flag signals. The structures on the cabin could be radio masts, although the taller part of the right-hand structure appears to have a cowl at the top.
There is no indication of the subject or its location. Given the Greek location of the other painting, it could be that this was painted abroad. It seems unlikely that this building still stands, so I am not expecting anyone to identify it, but if anyone can that would be great.
That it was among photos from the Pritchard family is not surprising. As can be seen from a newspaper article, they were always interested in new technology, which in the late 19th & early 20th centuries included wireless and flying. I have uploaded the article and an accompanying photo of members of the family with a balloon. The article is at www.ipernity.com/doc/philsutters/39796278 and the photo next to that.