Sandals designed for water sports are a great choice. I’d recommend Teva’s which are designed for whitewater rafting. There are lots more options here from waterproof socks that can be used with any footwear to neoprene booties that are designed to keep your feet warm when wet.
But if you are really getting into your paddling sports or recently won the lottery, then a set of dry pants with builtin waterproof socks, are a superb choice and many of our guides use these. The dry pants will keep your legs nice and dry as the socks are a part of the trousers, your feet will also benefit from being kept dry and warm. The socks part of the trousers are pretty fragile so you need to keep your shoes or sports sandals on at all times to stop sharp wee stones puncturing the socks.