If your feet are not too tired!!!! Yes, it would be a great way to get back to the BC - IF the line for the boat is really long. If it's not a long wait for the boat yet, you may want to take it as it would be a Long walk back to the BC. But if the line is really long, it may end up faster to walk than to ride!
To take the walkway, go out to whre the buses are and take the left-hand sidewalk - follow this all the way around the water. If you look out across the water you will see the sidewalk that is well lite that leads to the Boardwalk - I would guess that from there that it would depend on which end of the BC you're on as to what would be the shorter walk.
-Kim