Narwal Robot Vacuum and Mop Narwal is a relative newcomer to the robotic vacuum market. It's a sweeping/mopping hybrid that is pretty impressive. It's expensive and hindered by a clunky, steeply learning curve application. To mop, you drop a detergent sheet into the base station's water tank that is clean. https://moprobotvacuum44790.ageeksblog.com/27201168/5-best-rated-robot-vacuum-lessons-from-the-pros