I'd like to suggest to not try this on your own unless you have superior sup surfing and river skills. Note the padding on Dan's body to prevent from nailing rocks on falls. Also, the falls he's dropping into is quite deep at the bottom allowing him to fall without hitting bottom or a protruding rock. I've even read of sup'ers wearing 'spine protectors' while doing whitewater. Scary.
If you're new to whitewater, take a sup river class, or a whitewater kayaking class prior to hitting a river. You need to know how a river works, which drops to avoid, and how to scout the section you want to run either prior to getting on the water, or/or while paddling. Best to go with experienced paddlers, and don't forget the helmet. Local paddling clubs might provide adequete instruction and buddies to paddle with. We lost a good friend over a year ago after he was pinned. Quite the trajedy, and he was a very experienced local instructor.