When it looks at the whale, the ocean floor sees only a black ellipse - a black belly - swimming off the continental shelf. The whale faces the dark bottom in a smooth and respectable shape -wearing the elegant cloak of simple capillary action. The pressure from the seafloor pushes back against the skin. The skin buoys. Gravity is somewhat relieved. Blood moves easily horizontally and vertically. The skin keeps the heart beating.

This would be, for us, cardiac bliss: lifelong bed rest; an endless stack of down pillows for elevated legs; a slightly-pumping talisman against vericose veins. But only slighty pumping, still.