Yes and no. Yes, in the sense that any craft you use around water can be dangerous if you’re careless, or you can’t swim well, or you push it beyond its intended limits in rough water or bad weather. But when you deploy them the right way, float tubes are safe and fun. Inner tubes are meant for skilled swimmers to use for relaxed fishing, paddling, and lounging in relatively calm water—they’re no substitute for a life jacket, and they’re not supposed to be used to travel any significant distance. Even river tubes should not be used in very swift or very cold water.