Turner Sink, June 3, 2006

WKPP Update: Turner Sink, June 3, 2006


Update by Casey McKinlay

April, 2002

…On July 27, 2002, approximately a month since its last outing, the WKPP decided to set Turner up for a major exploration push the following weekend while checking conditions upstream from the sink. Conditions were excellent as Jablonski and McKinlay traveled upstream towards Innisfree after placing a number of bottles in the cave for the following weekend. All the pieces were in place and confidence was high that the following weekend would be the real deal. The setup team of Marc Singer and Steve Serras was provided with the remaining cylinders to place the following Friday before the big push.

On August 2, 2002, McKinlay arrived at Extreme Exposure in High Springs to top off an extra argon bottle, top off his breather doubles and pick up a new DUI C-400 undergarment. Everything was on schedule for the exploration dive. Irvine had just called and was leaving Ft. Lauderdale; Jablonski was on his way to meet McKinlay at Extreme Exposure; Singer and Serras were in the water at Turner placing the gas for the dive. The biggest question was whether the team had enough line and where to eat dinner in Tallahassee that night. The pieces were in place and the plan was solid or as Irvine would say, “bullet-proof.”

A few minutes later McKinlay took a call from Jablonski. Singer was on the phone and the report from Turner was the system had gone tannic. They would go ahead and pull the equipment. Exploration in Turner was once again interrupted, expectations high as to what was to be expected once the system cleared.

Quest, Spring 2003 Issue” “Turner Sink, Doorway into the Unknown”

June, 2006

Precious few assaults had been mounted against the labyrinth of Turner Sink; the cave had only seen two notable exploration pushes in 15 years. The first exploration was conducted by Gavin, Irvine and English in 1992 and the second by Irvine, Jablonski and Mckinlay in 2002. This enigmatic sink was the last of the big caves in the WKP to clear; this together with a heavy emphasis at Wakulla Springs and difficult logistics at Turner discouraged regular exploration. This was a long time to wait for a shot at serious exploration. Turner Sink is the southernmost entrance to the Leon Sinks Cave System; exploring south would help to answer important questions being asked by a range of state and federal managers. Over the years, Turner had come to represent both the key to unraveling the secrets of the Woodville Karst Plain while also epitomizing exploration in the WKP. There is nothing glamorous about Turner Sink. The spring basin is small, shallow and isolated; it quickly drops to zero visibility and remains that way for hours. The entrance to the cave is restrictive, requiring single file travel and minimal gear; this also complicates decompression logistics including a prohibition on a habitat. The actual decompression is more complicated, with 40ft being the shallowest depth within the cave for deployment of a small trough; the slow ascent from 30ft to the surface are be conducted in nearly zero visibility with divers often resting in the mud. Support divers need to be comfortable operating in zero visibility for many hours while moving equipment and divers in and out of the cave. These divers must be especially prepared for emergencies. This cave requires the best support divers within the WKPP. Typically setup was completed 24 hours in advance of an exploration dive; this allowed the basin and the cave system time to clear. Multiple teams were usually impractical, placing additional limits on diving efficiency. The layout was rough, primitive and everything Wakulla was not. The tradeoffs on the other hand were priceless for the WKPP cave explorer: this type of cave could not be found anywhere in the world.

Negotiating the basin and entering the cave system was much less problematic if you were the first to do so; additional team members are left without visibility during the entrance. However, upon clearing the restriction, you enter the cave through a side wall at a depth of 50ft. Directly across from the entrance is a staging rock where scooters and drive bottles are staged in advance of the dive. At this point the tunnel opens considerably into a large borehole-shaped cave measuring 40ft wide by 20ft tall with a noticeable flow pulling the diver into the cave. Particulate disturbed during the ingress blows downstream; this particulate, together with black walls that reflect very little light, reduces visibility. The rust-covered deco trough is positioned at 40ft on the ceiling directly above. Due to the depth and cave logistics it is not feasible to place a trough that is much use for decompression. The trough is more of a pit stop enabling divers to eat prior to moving into the muddy basin where the last few hours of decompression are spent. After loading up with equipment at the staging rock, the 1,000ft journey downstream is pure “Leon Sinks, Monster Tallahassee Power Cave.” Within 200 feet of leaving the staging area, the floor drops away almost immediately. Several hundred feet downstream the 70ft decompression bottles are visible on the left wall suspended from the line in the dark. After another 500 feet, the cave winds left and drops to the 100ft where the 120ft decompression bottles are visible on the floor. Several hundred feet further, the tunnel corkscrews back on itself and drops to 190 where the transition from 190 travel mix to the 300ft mix takes place. From the 190′ drop the line heads down at a 45 degree angle, remaining at depth for the remainder of the dive.

The remote and unrefined nature of the cave system, in addition to the extremely poor visibility in this section of Leon Sinks, made Turner Sink an almost impossible dive since its discovery by WKPP explorers Steve Irving and Tim Norkus in 1992. Wakulla had been the priority for much of the late 90’s while Indian Springs, Big Dismal, Cheryl and Chips Hole had been the priority for most of the early and mid 90’s. While the potential was known, there always seemed to be a hot (easier) priority elsewhere in the WKP. Given Turner’s location together with its size and flow, the assumption was that Turner was not going to be difficult to figure out; “it goes south and takes all the water in Leon Sinks with it”– at least this was the general assumption. Wakulla Springs, on the other hand, contains easier logistics given the large basin and simplified entry. However, Wakulla exploration is also relatively complicated with numerous intersecting tunnels. Wakulla made the WKPP work for every inch of cave; in fact, it continues to this day to represent this same complexity. Numerous extreme dives were done at Wakulla at distances greater than 15,000′. Many of these dives proved punishing with long decompressions, extremely limited visibility and elusive cave passages. Likewise Chip’s Hole proved equally challenging, requiring push divers to sustain significant physical abuse Like Wakulla, Chip’s was difficult and often played hard to get. Turner Sink, despite its logistics, presented divers with the most consistently large section of cave ever discovered. Moreover, the payout was significant with a main conduit that did not regularly loop back upon itself. Turner was difficult but relatively predictable, providing one possessed sufficient motivation. In the end, Turner is less mysterious but without any of the convenience of Wakulla, presenting seemingly unforgiving cave. Since the earliest days it was known as the epitome of Tallahassee Power Cave – a raging siphon that was big, deep, dark and scary.

May 31: Recon

Aware of clearing conditions in the WKP, we decided it would be in the WKPP’s best interest to evaluate exploration options in Turner Sink. We had just come off several productive dives in Wakulla including the discovery of Q-Tunnel, yet we needed to understand where Leon Sinks was trending in relation to Wakulla Springs and the newly discovered Q-Tunnel. We enlisted the assistance of Derek Bennett and Robert Bognar and headed to Wakulla County for a recon dive.

The trail back to the sink was rougher than usual, but there were plans to clear and widen the trail before the weekend. As we geared up, I noticed the sink was covered with invasive water lettuce which I had not seen before and plans would need to be made to clear some of this obstruction. Working to clear the water lettuce, we notice a very good sign. The basin was clear below the milky layer covering the first 5ft of depth. The visibility was good and flow was noticeable but not excessive inside the entrance to the cave itself. We decided to motor upstream to confirm the location of the incoming line from Greyhound Sink on the adjacent property. WKPP explorers Marc Singer and Dave Sweetin had linked the sink into the cave system a few years earlier but visibility was zero and the physical confirmation was never established. We stopped in a few spots to mark some leads and fix broken line and quickly established the location of the incoming Greyhound line almost 2,000ft upstream. We turned and headed back to Turner to check the line downstream to the dropoff and double arrow the drops for the 70ft and 120ft decompression mixes. The line looked good all the way to the dropoff so we returned to the entrance and lifted the trough to the ceiling with a pair of Halcyon lift bags. The dive was productive and the conditions looked good enough to take a shot later that week. I hardly had time to notice but I sensed from the silence that Derek and Robert were struggling to stay focused on the tasks at hand; the first dive in Turner tends to be distracting

June 2: Setup

(Cox, Mudry) Setup would be relatively quick but both divers would need at least one clear look at the layout of the sink and entrance restriction before moving the gear into the cave. The first gear trip would blitz the sink and require touch contact thereafter. Jarrod and I decided to send them in with the FX1 camera to capture clear video of the sink since we had no video record on file. The plan worked well and we got the video; the guys got a quick orientation and went to work on the gear placement. Over the course of the next two hours they placed a dozen decompression bottles, 9 drive bottles and 8 scooters. This allowed the exploration team to enter the water first thing on Saturday morning with a 190 bottle each and the video scooter; saving both time and visibility. We owe a huge thanks to Scott Cox for making the last minute schedule changes to help us out and to Doug Mudry for his consistent support efforts. Everything was placed perfectly and the stage was set.

June 3: Exploration

(Jablonski, McKinlay, Rhea) Objective: travel downstream approximately 4,500ft and begin exploration. Time permitting, capture video and verify 2002 exploration survey. Given the addition of a third diver (David Rhea) on the exploration team, I decided that I would survey into the cave while David handled video and Jarrod explored the passage ahead. We decided a 3 drive, 3 scooter plan would be best: not overly conservative, but enough to keep things from getting out of hand. We were also unsure what the line would look like and whether we would end up wasting a lot of time repairing the line along the way.

We geared up early before things started to heat up and departed by 9am. We gathered all the drive bottles and scooters at the staging rock and motored downstream to the dropoff. Somewhere along the way I broke a blade on my No. 1 scooter but failed to notice until we dropped down to 190′. Broken blade history seemed to favor Jarrod more than me, so I let Jarrod and David know I would be leaving this one and going with No. 2. After a few minutes of discussion we head into the blackness, dropping to 240′, then 260′, and then 280′ as the strong flow pulled us downstream.

Around 2,000′ downstream we came across a pair of safety tanks left by George in 2002. The tanks looked rough and would need to be removed. I remember watching George put them down in 2002 and thinking it will be nice to have those when we push the cave in a few weeks. I noticed the line was broken and the without hesitation the three of us went to work. I motored downstream to locate the other end while Jarrod and David prepared the upstream end. Both were located quickly and I recall asking (through the RB80 mouthpiece) whether this was part of the GUE Cave 3 curriculum; downstream in a siphon, loaded down with bottles and scooters on the way to explore cave but taking a time out to practice line repair. Neither seemed amused, so we hit the trigger and moved on. It did not seem to take very long to reach the end of the line from 2002. I took notice of the end of the Gavin/Irvine/English original tie-off up high on the left wall as we passed and strangely enough recalled the strange, brown rock outcroppings where Jarrod had ended the line 4 years earlier. We made quick work of the drive and scooter switch while Jarrod removed the tape from the Magnum exploration reel, David fired up the Mini-Mee video scooter and 50W video light and I pulled the survey book out. The tunnel made a 90 degree turn to the right at that point and remained about the same size as the previously explored passage: 40′ wide x 25′ high. The tunnel twisted for the next couple of survey shots, which had me concerned from an efficiency standpoint. If the average distance between stations stayed under 100′ it was going to be a long dive. Fortunately it would turn out just the opposite as I rounded the next corner and the cave blew wide open. I thought I could hear Jarrod laughing loudly and wondered if it might be me laughing to myself; I knew for sure there was nothing but silence coming from David Rhea.

The cave blew my mind and it was difficult to focus on the job at hand. The right wall and ceiling were not visible most of the time as Jarrod stayed left. The floor for that matter was not easily visible either which, was not necessarily a surprise until I started paying attention to the station depths: 275ft – 285ft – 280ft – 270ft. The floor at some stations had to be 320′ and possibly deeper. I had not seen these depths in any of the WKP systems until this dive. The walls and relief were incredible, remarkable phreatic features not unlike what we had seen a few weeks earlier in the largest section of Q-Tunnel. There were obvious indications that large volumes of highly reactive water have been eating away at these walls for thousands of years. It was a remarkable experience to be the first to witness such beauty. We hit the end of the first reel and Jarrod prepared the second for deployment. Jarrod headed off again with the second reel as I waited to see which direction the cave was headed before I could get the shot. At times it became inconvenient to stay too close because the cave was so large that it took Jarrod time to figure out which way it was headed. I also received subtle reminders at each station that we were in a siphon, requiring me to slow up about 20ft in advance of the station so I had enough time to get the info and take the shot before getting slammed into the wall or spun around backwards. The draw became more noticeable as we continued further into the cave. Given the depth, we would need to keep track of time and gas more closely than we had in Wakulla. Time seemed to fly but it had been close to two hours since we tied in the first reel. Jarrod was now emptying the second monster reel. Gas would dictate the turn as Jarrod jokingly made an effort to take the 3rd reel off my side. There’s a reason why the survey guy carries the 3rd reel, not to mention a better reason why the project director carries the 3rd reel. Jarrod completed the tie-off on the ceiling in a perfect location where the ceiling formed a large arch. The cave ahead was monstrous and black with no indication it was about to let up. I pulled the commemorative arrow from my right pocket, placed it on the line, shook some hands, switched drives and suggested we get the hell out of there. As we motored back upstream, both Jarrod and I noticed that in the frenzy, I neglected to place a single line arrow along 6,000′ of newly explored cave passageway. I could excuse my action by saying there was too much to look at or I could justify the decision by saying that any confusion as to which way was out was resolved by seeing which way the strong current would pull our team.

The pace back was reasonably quick as we stopped in only a few locations to drop arrows and mark additional exploration leads. We noticed a monster lead on the west wall about 6,500′ downstream. The entrance was deep, maybe 325′, with large, sharp limestone outcroppings. I wondered whether this might be some sort of connection back to Chip’s Hole or perhaps an incoming dark water source. We would need to check this out on another visit because it was time to go. We picked up the gear at the first drop and I resurveyed the 2002 line while we headed for the 190 bottles. Bottom time was 210 minutes at an average depth of 280ft. Turner was back open for business and quite possibly the largest, deepest, and most continuous section of pure conduit yet seen in the WKP. Conduit that large for that distance was unheard of and we were able to explore more cave during one dive than in the history of the WKPP; this may also be more cave than has ever been explored at one time at any depth.



Decompression in Turner cave takes a little getting use to, especially after spending so much time in the relative comfort of Wakulla basin. It’s not realistic to switch off your light while on deco in Turner so it was nice to have custom made Halcyon 30amp primaries capable of burning 12+ hours. As we hit the 140′ stop, the support and video team dropped in to greet us and share in the good news. Both Magnum reels were empty– which typically speaks for itself– but the entire exploration team was fired up. The excitement carried over to the support team and eventually on to the guys on the surface. This was a big day for the WKPP and the result of patience, meticulous preparation and most of all solid, unselfish teamwork. The recon, setup, exploration, in-water support and surface support contributed to the success of the exploration and in the process made history.

Thanks to Anthony Rue, Doug Mudry, Robert Bognar, Kell Canty, Mark Messersmith, Chris Werner, Scott Cox and Jim Miller for an exceptional effort. Special thanks to Jim, Scott and Chris for wrapping up a long day of exploration work at St Marks and gearing up for the late Turner shift. Seeing Jim and Scott come through the restriction to check on us and pull gear was a welcome sight. Having Robert and Doug at 20ft and 10ft in zero visibility for several hours made a big difference in terms of safety in the final stages of the decompression. Mark, Kell, Chris and the rest of the team extracted and packed all the equipment and Anthony captured some of the best post-dive surface interviews seen in some time.


The operation was tremendously successful and confirmed without a doubt the trending direction of the Leon Sinks Cave System. The compass indicated a general southeast direction with the majority of shots between 50 and 130 degrees. Data provided to Chris Werner and Todd Kincaid was immediately plotted on the map indicating a clear trend towards the southwest section of Wakulla Springs. Straightline distance between the P-Tunnel area and the end of the line in Turner is 15,000ft. Objectives going forward will be to identify an incoming north tunnel in Wakulla and explore north while continuing to push Turner south if conditions hold. Turner gave no indication that it plans to come up to a sinkhole and continues to get larger. If we can knock out the connection and answer 50+ years of speculation we can then focus on planning the 50,000ft swim through from Turner to Wakulla.

Special thanks to my dive partners Jarrod Jablonski and David Rhea. A few words come to mind but “solid” seems to sum it up best.

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