I know this guy down in the Yucatan, Mexico that is a pretty Xtreme mapper. Sam Meacham is a cave diver by trade, but has recently gotten into education. He is trying to prove to the powers that be (government, etc...) down there in Playa del Carmon, that pollutants that are dumped into these sunken pools ("Cenotes", Mayan word for "well") is eventually deposited out into the ocean, because much of the Yucatan is connected under ground by a vast underwater cave system. So he is trying to map these underwater caves and map how and where they connect. If you ever have the time and the space, download BBC/Discovery Channel show, "Secrets of the Maya Underworld"(this link will bring you to a page to download the movie). It is well worth the download and has some spectacular underwater filming. Though I should warn you, it is not for the squeamish/claustrophobic. There are a few scenes in which he gets stuck in a pinch.
I worked with Sam down in the Yucatan with all kinds of funky wildlife, such as pumas, scorpions and many fun poisonous snakes. And then there was the plant life, many kinds of things that cause a lot of pain and itchiness. Sam dives into one cenote and then surfaces at another mapping and gathering GPS points to create a map of underground currents that feed out to the ocean.
