Crossword puzzle clue "glass bottom"

"I don't believe in rock bottom. Rock bottom is like ___."

Bottom bottom line?

It may have a glass bottom

Florida spot noted for its glass-bottom boats

Glass bottom

Like the glass, when viewed by someone who's pessimistic about how much liquid is in the glass

Small glass disk used as an ornament in a stained-glass window

Level near the bottom of the minors, informally