JET SET: HANGING WITH THE NAUTILUSES

Rock Islands, Micronesia – The divemaster hands me a nautilus. Cream-and-caramel striped, it's CD-sized, but thick-bodied, filling the curve of my palm. The cephalopod heaves within its chambered shell: one of nature's finest examples of a logarithmic spiral.

I fin over to one of the Sam's Tours guides. "It seems stressed," I scratch on a slate.

"That's how they move," he writes back.

True, nautiluses jet-propel by siphoning water. But any animal trying to jet this hard clearly isn't happy...

He releases the cephalopod. It bumbles downward, wobbling like a weak football pass. I descend and intercept, then hand off to my friend Robin. Together we examine its tentacles – maybe as many as 95 – bunched like wheat grass around the beak. It stops shuddering and protrudes more from its shell. Scent is a nautilus's primary sense. Maybe we taste like cage-bait chicken, even through all this neoprene and saltwater?

Finally Robin waves good-bye to the seven cephalopods. Along with her husband JD, we drift Shark Drop-off, which lives up to its name. We even blur past a cloud of 40 juvenile grey reefers: a treat, since few sharks school. The dive's a good one, yet I'm troubled. Is it fair to tractor-beam these animals from the deep, even if they can withstand it? Most live between 1,000-to-1,500 feet in 40°F-degree water. And we're spinning and poking them: 30 ft, 85°F...

Later I read Dr Neale Monks on the subject: "Animals very similar to the modern nautiluses were swimming the oceans when the dinosaurs walked the Earth," notes the paleontologist from London's Natural History Museum. "But the heyday of the nautiluses was well before that, around 500 million years ago. Clearly, this is an animal to treasure... Leave them in the sea where they belong."

Glad as I am to have experienced all this, now I agree. Once was enough...