@Tom66,
The area below the aquarium base was a bar + access to the elevator. I don't believe the inner tube extended below the concrete aquarium base. However I think there were curved glazing panels above the bar to give the appearance it did.
I agree that looks like a crack in the inner cylinder (right photo behind shard of outer shell). I did say "probably compromised" . . . IMHO the whole inner cylinder is scrap as its probably crazed with micro-cracks, and even if it isn't, the general public would never trust it unless it was completely replaced.
@AndyBeez,
The hoop stresses are easily calculable (without stress simulation software) if you take the known tank dimensions, and scale off them for the water level. However without knowing the details of the shell and inner cylinder to base joints, and also whether or not any of the weight of the two cylinders was supported from the top, its impossible to calculate the stresses there.
Wikipedia claims the water column was 14 m. That's only about 1.4 atmospheres pressure, or about 5% of the typical operating depth for a nuclear submarine in deep water. It is 40% more than the internal atmosphere pressure the ISS runs at. However neither application requires a transparent hull so comparison with them is totally irrelevant except to get a 'human scale' feel for the forces involved.