This hide is trickier than the other caches along slough, but it’s there. You will need to use your paddle to lift something UP to get the 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 should be able to get to this cache, find it and replace it without getting out of your yak. Unless the water is really, really low—then you might need to wade a bit.