You're not giving us much information to go on here. Your description gives us nothing except color and shipwrecked...
We all like to see photos, so please put some up. If I'm thinking of what you might have found, let me stick up a photo group or two, and perhaps something will look similar.
Sometimes stoneware has impressed maker's mark information, that may be of help.
So, come on, tell us about diving in Panama. What's the story on your wreck? They've uncovered some cool stuff in those waters...