Airhead BOB 4-rider Tow Rope with Buoy for larger towables. So what about BOB? BOB is an advanced 4-rider Tow Rope with inflatable buoy in the middle that will boost your towable's performance to a whole new level. The buoy keeps the Rope out of the water while towing, reducing drag, rope spray, and submarining. This 60 ft. enhanced towing system has a 4,000 lb. break strength. BOB features a heavy-duty full nylon cover, self-bailing drain vent, and speed safety valve for fast inflation and deflation.