CNN At This Hour With Berman and Michaela April 18, 2014 15:19:00
Was a ship that took on water, it also had vehicles and what you need to understand about these ships is that in order to have vehicles on the vessel, you need a very large deck space. typically close to the water line. you don't need much of a breach in the hull to introduce water that if you only have 1 to 2 inches of water on the vehicle deck of a ropax ship such as the sea wall -- and as in the case of the herald of free enterprise, in that case, the vessel sunk within 90 seconds once water ended up getting into the vehicle deck. it's something that's called the free surface effect. you ha...
Source: archive.org