I love my Keen Newport H2 Sandals! I bought them just before my trip to Costa Rica, and they were perfect for rafting, playing in waterfalls, & a hike through the jungle that included walking through creeks, climbing rocks & heading down trails. The open back does allow debris to get under your feet, but it's also easily removed. When the humidity was high, it took them almost 2 days to completely dry out, but otherwise they dried in a day. They were still comfortable to wear when damp, due to the neoprene lining under the cloth. As suggested on other reviews, I ordered a half size larger than usual to get a good fit.