The following article was submitted on September 1, 1998, by invitation, to Descent magazine (an international caving publication produced in the UK). The editor changed the article to "present tense" in anticipation of the October, 1998 publishing date which coincided with the planned start date of the expedition. Because the expedition was postponed due to poor visibility resulting from two storms, the present tense form of the article was inadvertently misleading. The edited article appeared in the October/November, 1998, issue 144.

On October 1st, 1998, underwater cave mapping will be revolutionized as the Wakulla 2 expedition begins at Wakulla Springs State Park, Florida, USA. The cave has been explored to 15 km[*] and continues on with no sign of ending. Wakulla 2 will use an automatic, digital cave mapping device that was custom-designed for the project. The 3D Mapper, designed by Cis-Lunar, has 32 sonar transducers spiraled around its nose which fire 4 times per second gathering wall distances. The device tracks its location with an inertial navigation system using ring laser gyros and accelerometers. Industrial nickel metal hydride batteries provide power and run the integrated propulsion system that moves the device and diver through the water. In fact, the propulsion end of the mapper is identical to the scooters that will used by the exploration and safety divers that will accompany the mapper-driver on each mission. The range for the "Fat Man" scooters is a whopping 20 km.

Life support will consist of a novel system of two Cis-Lunar Mk5 rebreathers per diver -- the primary rebreather is integrated with the Fat Man scooter; the backpack-mounted MK5 will only be used only in an emergency. Special equipment has been developed to permit divers to dis-connect from the vehicle-borne rebreather and reconnect to another while underwater, thus permitting, for the first time, an underwater transfer of rebreathers between diving partners in an emergency. Rebreathers re-circulate the diver's exhaled gas, and oxygen to make up for that oxygen used, and scrubs the exhaled carbon dioxide from the gas. Depending on the metabolism of the diver, each Mk5 has a range of approximately 8 to 12 hours, independent of depth.

The term "gas" is used, because the divers won't be breathing air. Rather, they'll use a mixture of 88% helium and 12% oxygen[**] to avoid the problem of nitrogen narcosis. The cave rapidly descends to nearly 100 m water depth shortly inside the entrance. In addition to narcosis problems, decompression during the return to the surface is a serious concern. The expedition will be the first caving endeavor to use a saturation chamber. The system has been designed to float on a barge at the cave entrance. A transfer capsule will allow divers to leave the water at a depth of 40-50 m and decompress in a gas-filled chamber. When mapping and exploration have extended the distances to be traversed, the divers can stay pressurized in the chamber for a period of approximately 2 weeks. There would be little decompression needed after each dive, but 3 days of decompression would be required after the crew's mission was done before they could re-enter the outside world.

Support divers will help the exploration divers when they return to the transfer capsule. The support divers will retrieve the mapper and return directly to the surface where the survey data will be downloaded via a laptop computer. At Mission Control -- a temporary office complex set up on site -- the data will be converted from wall distances to actual points in 3D space. These points can then be displayed on a Silicon Graphics computer to form a "virtual cave." Updates of the map, and the progress of the expedition, will be published daily, beginning October 1, at www.wakulla2.org.

*This statement, particularly in the edited version, has been misconstrued by some to suggest the Wakulla 2 project claimed credit for the original exploration of the cave system. Clearly, in the original version given here, the previous sentence indicated that the expedition was a future, upcoming event, whereas the 15 km of exploration occurred in the past, and therefore, was conducted by others. The 500 word limit for the article given by the editor resulted in this article focusing on upcoming project (in particular the mapping system) not on a historical summary of past exploration. For a more thorough discussion of the history of the ~40 years of exploration at Wakulla Springs, the interested reader is directed to:

Stone, W.C., Ed. The Wakulla Springs Project, published by the U.S.Deep Caving Team, Inc., January 1989, ISBN-0-9621785-0-0, Library of Congress Card Number 88-051320. 220 pages, hardbound. Second printing presently available from the NSS-CDS bookstore, Cave Diving Section of the NSS, P.O. Box 950, Branford, FL 32008

Woodville Karst Plain Project website

**As diluent gas

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