I see something floating up to the Beach, and this thing is huge. Standing about 3 meters high, this is rather like a huge cushioned hamster ball for people. This is a serious sport device for some serious fun. The center shell features two harnesses, so you and a friend can experience the rush together. While it is cushioned, safety cannot be stressed enough while using this, and common sense would suggest a nice long very gently sloping hill away from obstacles. The Rolerball (yes, one "L") will set you back about $1798, and you can find more information here: Dual Passenger Rolerball. Hey, there are some sandy slopes close by the Beach that would be perfect. It may take a little while to roll the Rolerball over there, since carrying it is out of the question. However, coming back down the slope will no doubt be a different story.
Aloha from the Beach,
greg