Others are routinely raided for birds' nests, whose perceived aphrodisiac qualities bring top prices in China. Insufficiently funded by government grants, Iliffe's globe-trotting trips are invariably done on a shoestring. You can go on more dive trips this way. Cave divers tend to be a hardy lot. Just to become fully certified, Daniels and fellow student Michael Loeffler traveled to Ginny Springs in northern Florida, home of the United States' longest underwater caves.
Most students drop out before then.
Most of Iliffe's work is less dramatic. Upon returning from a trip, he sends the animal specimens he's found to a biologist at the British Museum. He also analyzes samples taken where salt water and fresh water come together and documents what he finds, sometimes with the help of those who went with him. The officials have begun a program to identify cenotes whose beauty and safe diving conditions will attract cave divers from around the world. It is a program, like many in developing countries with impressive cave systems, that leaves Iliffe with mixed feelings even as he contributes to it.