Both you and @radix@lemmy.world came to the same conclusion I did that “operating astern” might mean “we are slowing down” but the impression I got from Wikipedia was that flag was for literally travelling backwards, and the ship is clearly not doing that.

Interpretation 2 is that the first flag is the blue Peter referring to obstruction (usually fishing nets) and it is instead a reference to Jucika herself, kind of a “hey, you, the thing in our way”.

Interpretation 3 is the in-port meaning of the same flag, which is “come aboard”

The third flag about having a pilot aboard is also a little weird and I can’t be sure whether he’s saying the ship has crew or whether they’re asking if she needs guidance back to shore.

Still fairly mystified by Jucika, especially the spotted neckerchief. Spots don’t seem to be a good match to anything.

… though I do like the idea that the shorts mean she might be calling herself a firecracker.