Look for a cord which is tethered to the cache container. There’s another string hanging down from a previous multi-cache we had here—that one isn’t it. And you can ignore the cache coordinates painted on the bridge which are also from the old multi-cache.
Level 5 for terrain because special equipment is required (a kayak), but once you’re paddling, the difficulty is only about a 2, depending on how much gunk or logs you paddle through. Water levels vary, but you can get to this cache, find it and replace it without getting out of your yak.