Hi Denis
My photos of the ships that I am interested in, are stored by first trading name of a ship plus IMO number (each ship has a separate directory) up to 1999 and starting from 1947. (I rarely shoot ships that have no IMO number), Later photos I have currently saved by name and yob, but eventually they will go by IMO number as well. Most tankers I have already organised by first name and IMO number. I usually download only one shot of a ship under a certain IMO number per name.
So if a save a shot from here of a ship built before 2000 (or a later built tanker) it will go in the directory with the corresponding name and IMO number and only when the name on the photo would give some difficulties to decipher I rename the saved photo. In other words I have none of the problems you are describing. The default photo number is good enough for me, it also gives you some idea how long ago the photo was posted.
If it is technically possible adding a small photo to the comment could save some time, by not having to read comments to ships that do not bother me at all. (yachts, naval stuff etc)