Saturday, July 31st, 2010

Peacock: Cave Diving at its Best

Luraville (Global Adventures): Peacock Springs State Park has two major springs, a spring run and six sinkholes - all in near pristine condition. Cave divers have explored and surveyed nearly 33,000 feet of underwater passages, making Peacock one of the longest underwater cave systems in the continental United States. Other interesting sinks in the system are Pothole, Olsen, Challenge, and Orange Grove.

Peacock has three vents in a pool that measures 150 feet (45.7 meters) long and 90 feet (27.4 meters) wide. The cave entrance is near the north end of the pool and leads to a limestone shelf with an average depth of 20 feet (6.1 meters). Since the system is big, divers need time to really explore it, or just focus on the areas they are interested in. While Peacock has easy spots with wide tunnels and big rooms, the cave can be silty and demanding.

So let’s start easy: After entering the cave, divers will find themselves in a nice big room. If they stay left, they will soon enter the Peanut Tunnel, which is a heavily used for training purposes. Some instructors like to conduct “light-out” drills here, since most of the tunnel is practically silt-free and students will have a hard time getting lost. Nevertheless, this section of Peacock has its own charm and it is a good place to get going again. It offers a nice swim at an average depth of 35 feet until it drops to 55 feet in the breakdown room. Halfway down the breakdown room, a small tunnel shoots off on the right and connects to the Pothole Sink. Continuing straight ahead, divers will encounter two small tunnels on the left that connect to Water Hole III. While pretty, good buoyancy control is important or visibility will degrade quickly due to lots of silt.

In contrast, the Crossover Tunnel that is reached after a short swim following the Peanut line is wide open. It leads to the mainline between Olsen and Pothole Sinks. Jump reels are needed on both ends. While swimming through the Crossover Tunnel, divers will notice another gateway to their right, called the Dark Water Tunnel. After a nice swim, the tunnel will T into a nameless connector that dead ends to the right and leads back to the Olsen and Pothole mainline on the left.

Assuming that the diver followed the Crossover Tunnel and connected to the Olsen – Pothole mainline, he will soon surface in Olsen Sink.

Frank Martz and Tom Mount were the first divers to actually connect Olsen Sink to Challenge Sink. Tom Mount and Ike Ikehara also traversed the approximately 4,000’ from Olsen Sink to Orange Grove Sink first.

After taking a breath of fresh air, divers will find a very pretty tunnel on the North side of Olsen Sink. If they stay left, a short swim at a depth of 60 feet will lead to a junction. The tunnel to the left will continue back to the Crossover Tunnel, the tunnel to the right will eventually lead to the Peanut Restriction.

However, the main dive here is the Cisteen Circuit & The Wishbone. Two possible jumps will allow divers to visit “The Crypt.” The first tunnel is marked with a double line arrow; the second tunnel is not marked. At times, the Cisteen tunnel can be milky and visibility can be reduced. Since this is not a heavily traveled section of Peacock, the tunnel is in rather good shape. A visible tumble of rocks marks the Cisteen Sink.

Divers should be cautious: There are two lines coming up from opposite directions and travel the small Cisteen Sink slot together. The slot is small and very silty, and there is a potential for entanglement, with no easy rescue by buddies.

Continuing south, divers will pass the two entrances to The Wishbone traverse. Both entrances can look uninviting and visibility in The Wishbone can be reduced due to low or no water flow. There are low spots in the area where tannic water has penetrated the system and settled down. Divers will notice a definite temperature and visibility change.

Staying on the Cisteen Circuit, divers will reach the Nicholson Tunnel jump after passing a short dead-ended off-shot on their left. Both the Nicholson tunnel and the Cisteen Circuit lead back to the Olson – Pothole and a jump will connect to the main line.

Divers will find several large boulders and small tunnels between Pothole Sink and the Entrance of Peacock I. Shortly before ascending through the crack from approximately 65 feet towards the Peacock I exit/entry, a view to the left will reveal the way to the Well. This area can be confusing. While the floor is covered with silt like in most side-tunnels in the system, the walls can look like a honeycomb in areas.

Another interesting section is Orange Grove, which is now accessible by wheelchair. Quite often a gator hangs out in the basin and leaves a distinct clear path in the duckweed that covers much of the surface. The spring pool measures about 44 by 80 feet with an approximate depth of 45 feet. The somewhat murky water usually clears in 20 or 30 feet, and divers can tie a reel to one of the tree-logs.

While the main Orange Grove tunnel is accessible at a depth of approximately 68 feet, divers can also search for the entrance to the deep or “Lower Orange Grove” section on the far left of the breakdown area. The entrance is hard to find and somewhat restricted, and it leads down to a depth of almost 180 feet. The tunnel itself loops around under the Orange Grove main tunnel. The average depth of this advanced cave dive with lots of silt is around 140 feet.

The main tunnel, however, stays between 50 and 60 feet, which is somewhat consistent with the rest of the Peacock system. The Orange Grove invites divers to long swims. One option is the Distance Tunnel. The jump is slightly past the halfway point to the Challenge Sink at about 900 feet into the cave. Visibility is usually good in this section, and the tunnel is in good shape since not many divers venture out here.

The Distance Tunnel starts out high and wide, but it becomes more restrictive soon and fine silt covers the floor and ceiling. While divers can negotiate most of the “Distance Tunnel” using backmounted doubles, a sidemount configuration is preferable if they want to go “all the way.” Further back the tunnel has a low floor-to-ceiling height and more and more silt will be encountered. After the fork, both tunnels will narrow and turning becomes increasingly difficult. On the way back, divers can peak into the Maartz Offshoot, which is a narrow, winding, silty but very pretty tunnel. Of course, a reel is needed to make the jump.

If divers decide to stay on the mainline instead of jumping into the Distance Tunnel, they will reach Challenge Sink after another 900 feet or so. Really good swimmers can jump to the tunnel leading to "Woody's room" before they reach the Challenge Sink, but they have to be careful. A dead-ended tunnel that can only be negotiated using sidemount gear branches off to the right, and the whole section can be nasty! Since we don’t know this area of the cave well, we can only refer to the map.

While there are several tight tunnels and less frequented areas are covered by silt, the Peacock cave system typically has very large open rooms with white limestone. Many divers really like the section between Peacock and Olsen. The best way to see most of the system without staging is to start at Orange Grove, swim upstream to Challenge, then swim downstream past Olsen, Pothole, and exit at Peacock. However, this is a long swim and air consumption should be good so that divers stay within their role of thirds.

Last but not least there is Peacock III, a siphon which has bad visibility for most of the year. That is why the system is only infrequently traveled. The darker colored walls, combined with poor visibility make the cave appear much larger than it really is. Following the main line leads through a large passage, smaller than the Peacock main passage, but still of a good size. Divers will encounter a couple of places in the cave where surface rubble has washed down into the system during heavy rains. It is very interesting to see river rock in piles on the silt floor.

Taking the Henley's Castle jump which is in the middle of a large open room is impressive. Following the line for about 100 feet (30 meters) leads to a tie-off on a long jut of limestone, directly over a vertical pit to 130 feet (39 meters). With good visibility, divers can see the sides of the pit from the top, but with less than 30 foot (9 meters) of visibility, the sight of the line dropping vertically into the abyss is ominous. Following the line to the bottom of the pit, it enters a low bedding plane for about 50 feet (15 meters).

While the bottom is sandy, visibility can drop easily. Since the line in this section of the cave has been loose, it did move to the right of the tunnel at times, which is too tight for divers using backmounted gear. So divers need to spent attention when they venture out here.

At the end of the bedding plane, the line drops into another pit, reaching 181 feet (55 meters). The second pit is a little less vertical, but still very impressive. The line is tied off at the bottom, but the passage appears to continue.

Peacock is a state park and requires a $5 daily pass. The cave system can be found at Lat. 30° 07’ 23.62” N, Long. 83° 07’ 59.35” W.

Peacock Springs State Park

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