There is an obvious danger of ship squat. The danger of grounding due to decrease in under keel clearance of the vessel.

To fathom the danger that ship squat can pose to the vessel, one can go through the incident of sinking of RO-RO vessel "Herald of Free enterprize".

Briefly the ship's  forward loading door was not closed before departure. As the vessel departed and increased speed, the forward freeboard reduced due to the ship squat. Soon water was rushing into the ship through the open door and soon after that ship capsized.

193 people died in this incident mainly because of Hyperthermia. 

So in this case squat resulted in capesizing of the ship.  For more information on ship squat and what caused the ship squat, read this blog "5 Questions that can help in understanding of ship squat"