What's This Thing Doing?

This barge can be seen from the beach at the end of our street.  I am not sure when I first noticed it, but today I walked out on the beach at mid-tide and then walked north toward it and took this photograph.  In the high resolution version I can see what looks like wood pilings in a random pile on the deck of the barge.  I wonder if the machine is pulling old pilings out of the water.  I asked a friend who might know, and I will be sure and let you know if I find out.  At least it makes the "landscape" look different for a bit.