The StraitEdge, StraitEdge Angler and StraitEdge2 inflatable kayaks can handle up to class III rapids, but are designed to be a sit-on-top type kayaks for open water use.
They can be used in rivers, but are designed to paddle straight, whereas most whitewater kayaks are designed with excess rocker (raised bow and stern) to allow easy turning.
The StraitEdge kayaks are designed to paddle just like a sit-on-top hardshell kayak. They have a rigid bow and stern that lengthens the waterline and dramatically improves the tracking performance. They are great for fishing as they are very stable, durable, and allows easy access to gear.
If you are interested in serious whitewater, the Attack Whitewater is the custom designed whitewater inflatable kayak.