http://www.amazon.com/s/?ie=UTF8&key...sl_3bvxd77iq9_e

The only Crocs I would consider are these Quicktrails which are an actual shoe. I use them with Simms neoprene wet wading socks, which are fairly heavy and come up mid-calf. As I backpack and fish, I find these work quite well. I use them for fishing, not just crossings, so they're a proven commodity to me. Anything with an open back or straps would make me cringe, as I've lost sandals to mud and current/rocks. You can screw in 8 or so short aluminum hex head sheet metal screws for excellent traction on slippery rocks if needed. That's safer than any boot other than real wading boots used specifically for fishing. Another option is felt. You can buy felt replacement kits for wading boots and felt the bottom of wading shoes with the provided barge cement. Felt is excellent on slippery surfaces and would aid in river crossings. Weight penalty, but safety increased. I wouldn't bother for 2-3 step creek crossings, but if you're negotiating something that is truly dangerous....