Re: What's sixze got to do with it?
I was going to comment on this, but you've got it essentially correct. It's to do with the curvature of the pressure hull; like an arch, the tighter the curve, the stronger it can withstand pressure. A smaller sub will withstand a greater pressure than a larger sub with the same thickness of hull.
On the other hand, the cube-square law applies: the bigger the sub, the more material it can have in the hull for the same buoyancy. That's assuming that they have the same arrangement of ballast tanks, of course, but then it's relatively easy to add more tankage in the design.
Biting the hand that feeds IT
