Wakulla at 39,000 ft (George Irvine)
WAKULLA SPRINGS CAVE JUST GOT LONGER – 39,000
by George Irvine
Date: Sun, 28 Jun 1998
Wakulla Springs Cave is rapidly rising on the list of the longest underwater caves in the World, and certainly is getting right up there with Leon Sinks as one of the longest deep underwater caves. After this last dive by the WKPP, Wakulla now has 39,000 feet of surveyed and mapped passage.
There are now two tunnels that extent over 14,000 feet from the entrance. Diving the Halcyon rebreather and tripple Gavin scooters, George Irvine, Jarrod Jablonski, and Brent Scarabin again travelled undeground down(town) to the intersection at Cherokee Sink and took the westbound tunnel this time. Last time it was the southbound tunnel that produced the 14,230 foot dive. This time , the tunnel went around Cherokee the other way, and then headed west , jogging north and west , back towards Leon Sinks. It was outflowing dark water in giant bore tunnel varying from 250 feet deep to 295 feet deep. The team added 3340 feet of line trying to take the northern splits each time an intersection appeared before finally making a wrong turn and hitting a dead end at 14,040 feet. Marking leads on the way out and writing them in the book, the group found four more large tunnels that could be the Leon Sinks connection point. Right now the cave is syponing this water to the south down the main passage, but one can now see where the dark water is coming from when the cave is blowing.
The dive took 252 minutes of bottom time ( bottom time starting when B Tunnel is passed ). B Tunnel is where the first deco bottle is left, a trimix mixture, as are most of the WKPP deco gasses. The dive was exectuted as follows. On Thursday night after 5:00 the WKPP met at Wakulla and put the gear together. Barry Miller, Ted Cole, and Jules Tomsits took the safety scooters and new safety bottles to 3500, John Rose , Bill Mee and Chris Warner took the rebreather drive bottles and large Gavins to 3500, and the rest of the deco gas was placed for all teams. Each team then explored various tunnels on the way out. Early the next morning, George , JJ and Brent went in and picked up this gear, moving it forward to 6500 for the switch while a team of Landon, Head and Werner conducted a simultaneous exploration dive in D Tunnel. All gear was left in the cave until the Park closed and was then removed Friday night.
Visibility was very poor all the way out. It had rained a couple of days before, and already the dark water had moved back into the cave, but was beginning to syphon back out again. Anyway, the trip was an on-the-line drill, but good speed was maintained. On the way in every lead was checked , so it took about 110 minutes until they reached the first tunnel to be explored, with the plan being to do the others on the way out if that one did not go. It turned out to be the motherlode of new cave which will keep the WKPP busy in there for years to come.
The new section was spectacular Tallahassee Power Cave (TPC). It would vary from Indian Spring sized tunnel to the black voids we have have come to know and love. At several points Brent Scarabin reports seeing no walls, no ceiling, and no floor while being at 285 suspended in darkness, just heading for the darkest spot. On one shot George reports stopping to clear his mask , thinking it was fogged, only to find it was not, but that the floor was nowhere in sight with 295 on the depth guage. Brent says at several points he stopped and tied off the reel and let it hang until JJ and George got to him to decide which way to go at major intersections.
The only problems reported on this dive were Brent hitting his head on a stalactite, and George reporting running his rebreather into stalactites that he could not see hanging down due to reading the compass while scootering. These are not the Mexico syle calcite pencils, these are the stop-you-dead-in-your-tracks version that are black and can not be seen. These things are concentrated at certain locations in the cave and appear unexpectedly.
A greet team met the exp team, and then went on to take photos in B Tunnel. The cleanup team of Cole, Barry , Trout and Chris retrieved the gear from 3500. The dive took about 100 cubic feet of bottom gas, which comes out to an effective .025 SAC rate, or eigth times leverage on an actual rate in the .27-.33 range, a fact of life which makes the 33 safety bottles in the cave about three times the gas required to get out, not counting the on board supply assuming tripple rebreather failure. The scooter logistics are such that at any point, any scooter the team had with them could make it back to the last scooter, safety scooters not being counted in that figure.
For deco, the team used the WKPP method for the deep part, and then an accellerated Hamilton for the intermediate, with some experimentation in the final stages done by George. Bill Mee has come up with supporting physiological and hemodynamic arguments for the deco that George has actually developed, so this was used as a basis to try something a little faster. Here is the result: George was able to completely decompress from this dive in 8 hours and 45 minutes ( this was a 252 bottom time at 285, 262 miinutes run to deco, first stop 250 feet on the appropriate trimix). The interesting thing was that he did only 3 hours of oxygen time ( actually 132 minutes of oxygen, the rest trimix ), and got straight out from 30 feet with no stopping. The shape of the deeper sections of the deco, and the choice of gases, allowed the shallower parts to be stepped through faster. It is estimated that with the current WKPP deco method, the oxygen may in fact not even need to be more than an hour, but we need to see the bloodwork to be sure of that. JJ and Brent now use trimix for all of the non-oxygen deco, a fact which flies in the face of conventional deco theory. Bill Mee again has the information to support this choice.
NOTE: Before you try this at home, be aware that these three do a good bit of hard training, and have the cardiovascular efficiency as well as lack or any dcs preconditions, and have the history to support this activity.
George drove home after the dive, charged his scooters, refilled his five partially used bottles and one oxygen bottle, vacuumed the rebreather and charged the light and was ready for the next one.
WKPP will be back at Wakulla in a couple of weeks to work these leads , and will be hitting all of Leon Sinks in a concentrated effort in July and August. We need to take advantage of this drought and get the hard stuff knocked out. If any of you can take time off to help , there is some great diving to be done. The Florida Geological Survey. FSU, the Forest Service and St Joe Paper are all getting out the maps and photos for WKPP to work all of the normally hard to dive and hard to find sinks.
Thanks to the usual people for getting it done. Dawn will have the rest of the reports.