I use to run on the board walk in the Asbury/Belmar area all the time but it has been a few years since I ran this long there. One of the funny things about the run was how much fast I felt on the way back. I remember thinking that running on the boards should be easier. The way back was quick though.
After I was at around the 10 mile mark (a little over), I took off my shoes and ran on the beach. I did just about 2 miles on the beach. It was funny how non efficient I felt running on the beach, but my pace did not suffer too much.