The boardwalk will appear to end but actually your on a small island and the boardwalk continues again just around the next corner. This is right beside the trail, so do check around the next corner, for any muggles. Just another two hundred metres beyond and you will exit onto higher ground and into a mixed hardwood forest and more trails that run east all the way to Alexandria.
Cache contains all the usual, log book, pencils, sharpener and trade items. Enjoy.