Are you visiting, or living there? And do you know Polish? You do seem to be from Chicago...
Lots of scuba shops, starting in Warsaw. And clubs. They take their diving very seriously there.
We managed to get both our kids OW certified while we were living there, and even in English.
There's local diving in lakes and quarries; mostly in the Mazurian Lakes area, Silesia, and in the west. Baltic diving, though I never did any, I understand is cold, dark, and on net-entangled wrecks. But if you're living there, charter flights to the Red Sea are relatively reasonable.
The Polish equivalent of ScubaBoard (or one of them) is called Nuras (
FORUM-NURAS ::). Great place to make contacts, get local dive conditions, etc etc etc. But it's only in Polish, as far as I see.
Username "Mania" is a ScubaBoard staff member here, lives in Warsaw, is a tech diver, and speaks excellent English. Also a very nice person. Maybe send her a PM? Tell her Marek K referred you. I'm sure she'd hook you up.