This was supposed to be one of the crown jewels of the trip.  The sound is actually a complex of narrow fjords cutting into the Greenland coast.  We sailed in pea-soup fog all night and the captain was not sure is we could enter the Sound at all.  Fortunately, the fog lifted just enough to allow us passage.
In the Sound, we sailed between sheer, rocky walls, glaciers, and lots of floating ice.  I took far too many pictures, even though visibility was not the finest.  One of the more interesting spots was the village of Augpilatoq - possibly the most isolated place I have ever seen.  It has a population of about 180 and can only be accessed by helicopter nine months of the year.  We were told that their economy is based on seal hunting.  Since this was high summer (43 degrees, heavy overcast, rainy, and lots of icebergs) the village is accessible by boat.  When we sailed by, some of the villagers hopped in their outboard-powered boats and raced out to see us.  They tagged along with us for several miles - taking pictures of us taking pictures of them.
We cruised the Sound for over 5 hours, finally emerging in the Denmark Strait and the Atlantic Ocean.

Prince Christian Sound Photos