OBrien Sombero TubeOBrien Sombero Tube Bring the fiesta to the water with the Sombrero 4. Whether facing inward or outward, kneeling or sitting, this tube provides non stop fun for all riders. This unique tube seats up to four riders, and because of the various seating positions, all you have to do is switch seats with a friend for an entirely new experience. Unlike other sombreros, this one will keep all smiling faces in plain sight.