It's actually not 100% floating. It is attached to land masses and resting on parts of the shallower ocean floor. I do understand science, very well in fact and displacement is a very easy concept to get as you know. Unfortunately, if you want to use the whole use your brain comment, I would suggest doing so yourself before attacking what someone else has said. If something is holding itself up, the displacement of the object isn't 100% is it? I will use the glass of ice thing with you also, imagine freezing a toothpick in the cube, and putting the picks on the edges of the glass holding most of the ice out of the water, displacement isn't 100% at that point is it? Can you go under the northern cap? Yep. Can you go around it in a boat? Nope. Why? Because it is attached to land, and below on the continental shelves.