So, the "massive hole" in the starboard (which others have said is largely above the waterline) could have sunk the Estonia.
But the much larger hole formed when the bow visor fails couldn't have sunk the Estonia even in conditions with 6m waves[1].
I wonder how much water that "massive hole" would let in. What would the expected rate of flow be, even assuming that the thing was entirely below the waterline? How many gallons of water would be required before Estonia finally sinks due to the ingress of water from that massive hole? (Here, I'm assuming, contrary to evidence, that the hole was there prior to sinking and was below the waterline.)
Obviously, this is an open question to anyone who can give a back of the envelope estimation. It seems to me that the massive hole is a bit small to explain such a reasonably fast sinking, but, like Vixen, I'm just going with my gut. I'd be interested in whether I'm wrong.
[1] From memory, someone can correct me if I exaggerate the wave height.