Hmmmm.... you might be on to something Rich. Like the plastic six-pack holders that snagged storks and pelicans, a snorkel keeper can be a diver's last defense mechanism against predators like sharks, or even aggressive turtles. I'll have to study that one a little closer.
As far as the other replies, I sense a bit of sarcasm going on here. One guy even replied that he keeps his snorkel up his anus. I find this the least bit funny. I spent 3 weeks of my life researching older designs, from Navy emergency duct tape designs to techie neon green 80's dive stuff to the black silicone of today. I have submitted a patent on my new design and I won't be patronized by you all. Hell you guys are so behind the times you don't even know what Im talking about. Most of you still wear neon colors and believe that buddy diving crap I bet.
But, being a genius and expert techie diver that I am, listening to the snorkel up the anus reply gave me a new use for my snorkel keeper--- the techie diver's extra-leg constrictor ring. A necessity for plunging into caves that can get kinda hairy at times.