Spray is designed to debilitate a bear's other great strength - his nose. A dog smells 100 times better than a human. A bloodhound's nose is 300 times better than an average dog. An average bear's snoot is 2100 times stronger than a humans. A naturalist who gave a presentation to our guides said a human walks into McDonalds and smells food. A bear walks into McDonalds and smells EVERYTHING, down to the bubble gum the fry cook is chewing. Bear spray is like a lightning bolt to that olfactory system. That same naturalist said it would be like blowing a train whistle next to your head. So, again, not a bad thing to have at the ready in the dark hollows of a tent, RTT or not.