The sad thing is if she was 7 meters more left thw whole disaster wouldnt have happend.

Explination:

when a ship passes through the water it forces the water down and to the side (displacement) in the open ocean the affect is incredibly minor, but where zeebrugge is concernd its very shallow, so the water has to go some where so at speed it will ride up then over.

The herald was hiting 15 knots when she started to take on water, the test on her sister showed the problem, lack of secondary water tight door (now mandatory on all ferries as is water tight compartments and barriers.)

The roro concept was taken from the landing ships of WW2 and used to create car ferries, most have very flatish bottoms and can get into waters that are not that deep.

The vessel i served on was a roro frieghter she had a depth of 7 meters a similar ship in size and wieght but not of roro design would be atleast 11 or 12 meters draft.

Dart 8 was a 26,000 tonne roro frieghter herald being only 8,000tonne,

Thankfully the herald sank onto a sand bank if it hadnt then the ship would have completely rolled over and then well sunk with all onboard. (ship of heralds design and size would take less than 10 minuets to sink completely)

Thats why we call them RO RO RO vessels Roll on Roll off Roll over