They move unseen and unnoticed in the shadows...
They look just like ordinary people...
(Ominous music intensifies)
But when the time is right (when the AIS tells them)...
They show their true nature...
(Fade to black)
A: I will travel by car for more than an hour to see a ship, after I took an intercontinental flight for the same reason.
B: There's barely time to read a good book, as the places where I sit with a book are too busy with shipping.
C: Camera gear is usually in the car.
D: Sometimes strangers will come to me and ask me "Are you that guy that takes photos of ships?" (Or something like it, after all, I don't speak Japanese).
E: I will comment on ships' appearance, but will keep an open mind and accept any other opinion.
F: I also like photography, but don't really know how to use it.
There are also more worrying signs, and here's a legal disclaimer: nothing to be used as the proof of any wrongdoing.
When you trespass to take a good photo; when you enter a restricted area by screaming at the guard at the gate to let you through; when you photoshop a port entry permit to see a specific ship.
Also, when you tell the significant other that she's more important than the ships, but she has trouble believing you.