Looks like an interesting ‘alternative’ to thigh straps and a way of keeping the white water skirt from collapsing:
https://www.alpackaraft.com/index.cfm/store.catalog?CategoryID=52&ProductID=195
It doesn’t attach though, so it would become another thing to chase when all goes wrong, and wouldn’t let you roll like thigh straps. Looks like a good little accessory if thigh straps aren’t your thing though?