We are surprised (and saddened) by the unusually low discharge rate at Weeki Wachee currently.  For one, it means that aquifer recharge is more or less not happening.  In my opinion, the recent approval of large (>5,000 home) developments in the area will not help this situation.  However, this does mean access to the cave.  The entire team is excited about pushing the end of the line in the deepest naturally formed spring in the United States.

We have already started training new team members and acclimating them to the unique issues diving at Weeki Wachee presents.  My congratulations to the new team members that have already been able to gain access to the cave at discharge rates > 115cfs.

We are anticipating the lowest discharge rates ever for 2011.  That means more diving and more exploration.  Check back often to follow our progress exploring this amazing cave. 

In 2009, the Karst Underwater Research (KUR) team had just under 80 days of theoretical access (March 11 - May 28). During this period, the discharge at Weeki Wachee Spring dropped enough to allow the KUR cave exploration team to gain effective entry into the cave system beneath the spring. During this period, over 20 working dive days were conducted in a safe and efficient manner.

Based on KUR's direct experience, our team has determined that the safe cave diving can undertaken when the USGS Weeki Wachee Well (reference 283201082315601) stage level falls below 11.7 feet. As a point of comparison, the range of 11.5 - 11.7 feet of well stage is approximately 97 cubic feet per second (cfs). This equivalence is based on the well regression model for calculating discharge (Knochenmus and Yobbi 2001, SWFWMD 2008). It is important to recognize that a .1 foot fluctuation in the well stage can have a perceptible impact on the force of discharge, particularly at the restricted entrance area from the depth of 150 to 180 Feet Fresh Water (ffw). At 11.7 feet of well stage, the spring is viable to dive, but still far from easy. See further discussion of this topic under the "Diving Operations" section.

The 2009 window of opportunity varied in many ways from our two prior years (refer to Chart 1 below). We gained access earlier in the calendar year then either of the previous years (due presumably to the cumulative effective of the ongoing regional drought and a dry winter). Unfortunately, we also experienced earlier than normal seasonal rainfall which abruptly ended the season sooner than our two previous access intervals.

This year also saw a record minimum discharge on May 13, 2009 with the lowest recorded well stage of 10.67 feet (or 84 cfs per the well regression model). This eclipsed the previous record set in 2007 of 10.96 (or 88 cfs). It should be noted that discharge estimates using the well regression model applied to the USGS Weeki Wachee Well are considerably lower than the reported discharge for the Weeki Wachee River (USGS Site 02310525) and the well regression model appears to underestimate spring discharge, but it is a useful tool for judging diving conditions for Weeki Wachee Spring.

We could not guarantee that flow conditions would be conducive to access in future years. Given this uncertainty, rather than prioritizing further exploration during the 2009 access period, KUR decided to focus on collecting samples and video documentation of the system explored to date. The goal was to round out the body of information surrounding the spring to provide academia as well as the interested public with a richer appreciation of this unique underwater environment.

During 2009, KUR was able to:

• Capture over 30 minutes of high definition digital video in various portions of the system


• Confirm to two additional radio location sites to further validate the underwater survey


• Assist in effort to locate dye from the SWFWMD dye trace study


• Explored an additional 600 linear feet of cave, yielding a chamber along the East wall, just before reaching Helms Deep, where unusual cave formations were concentrated

Click here to view the entire 2009 Weeki Wachee Exploration.  As always, we thank our sponsors and supporters for making the exploration at Week Wachee possible.

Last week's dives were more training related, so there really isn't too much to talk about.  The real news is the video that was shot a couple of weeks ago by Liquid Productions.  It is breathtaking!  The beauty of Weeki Wachee never ceases to amaze me.  The colors, morphology and features are unlike any I have ever seen. 

In the collage of pictures below, you are able to see the beautiful striations in the cave wall, a diver inspecting speleo-crobes along the cave wall and some views of support divers removing gear from the cave after a mission dive.

Images are Copyright © 2009 Karst Underwater Research. All rights reserved.

This was the first week where we need to have 3 days of diving. Needless to say, we accomplished everything we needed to. A special thanks to Scuba West for making available some gear after one of our divers blew a neck seal on their dry suit. That simple act allowed us to capture video of the clean up dive which would have otherwise gone uncaptured. The clean up dives always have some moments we wish we could record.  The high definition video for all of our dives this year has been performed by a new 2009 sponsor - Liquid Productions, LLC.  

After successfully placing all necessary scooters, scuba cylinders and video equipment in the cave Thursday night, the team entered the water Saturday at approximately 4:40 pm. Our plan was to film the cave using four divers.  Two of the divers would be piloting Silent Submersion UV-26 scooters with attached Silent Submersion Death Ray 200W HMI lights for primary lighting.  The two videographers would be piloting Silent Submersion UV-N-37 scooters with dual Salvo Diving 50W HID video lights for lighting.  The high definition video was to be linear footage into the cave with two parameters: 1) not to exceed approximately 2000’ of linear penetration and 2) be back starting decompression no later than 90 minutes. An additional goal of this dive was to to perform another radio location.

Unfortunately, the dive plan had to be changed to one of our contingency plans (the picture to the left shows the team discussing contingency plans) as one of the videographers compromised their dry suit neck seal at approximately 160’ in the middle of Event Horizon. This diver was safely escorted to the surface by safety divers with all but a chill from the flooding in their suit.  Luckily, the diver was able to return to the water during the clean up dive to video the clean up dive in the the cave, the fissure and the spring basin.

After some period of time, the team entered the Helm’s Deep section of the cave, dropped a fresh battery pack for the radio location transmitter, then scootered down to the right side of the room.  The team circumnavigated the room to the left and was was able to successfully video many of the formations on the floor and the walls in this area. Upon arriving back at Helm’s Deep, the team moved the radio location transmitter from its previous location to about 100’ further into the cave and activated the beacon.

Sadly, it was later determined that the beacon either malfunctioned or was accidentally turned off during low visibility. We were not able to successfully locate the beacon. We will continue to test this area until we get a solid radio location.

As always this would not be possible without our sponsors, the staff of Weeki Wachee Springs State Park and our volunteers.  A huge thanks to all of our volunteers for making this one of the most complex dives thus far a complete success, all divers exited the water safely and over $100,000 in equipment was successfully returned to the surface.

Although the team had a slow start on Saturday, all missions were accomplished! Another radio location was made and a charcoal pack was removed and given to SWFWMD for analysis. Last week we had hoped to extend the exploration beyond The Pit but we changed plans to focus on the validity of our cave survey and performing some scientific tasks.

Entry and exit of the cave is getting progressively easier. Unfortunately, this is due to the reduced discharge and overall health of our aquifer (the picture to the right shows a clearly visible boil on the surface of the spring; today there is none).   The spring discharge and visibility inside the cave are directly related. When the discharge decreases so does the visibility. Currently, visibility in the cave is around 80'. Although, this may sound impressive, the cave is over 100' wide. As I write this, the USGS well that we use to extrapolate discharge levels is the lowest since data started being recorded in August 1966.

The team pulled their way in through the Event Horizon for the first time this year wearing their entire kit -- 2 low pressure 121 ft³ scuba cylinders, Kiss Classic Rebreather, argon cylinder and dry suit. Previously, we had tried to have the teams setup their kit inside the cave but we have learned that is not the most efficient use of time.

Last week we were very pleased that the radio location pinpointed the cave right where our map said it should be. We were not so lucky with this week's radio location. This week's radio location proved that our map is off -- that is the power of radio location and is why it has become so important for us this year. These radio location points are major accomplishments that help validate the survey and so us the necessary adjustments needed using the ground truthing. It definitely tops the list of data collection priorities, even though the sample ("speleo-crobe") collections and date sonde results are also impressive. The second radio location was taken at an intersection in the cave to an area named White Death.

The next task was retrieving a charcoal pack that was placed in the cave a couple of weeks ago. When the team scootered into White Death, they came in low and to the south. This route put the team off the line about 40’ but allowed a view of the area beyond the line which the had not seen before. Most of the entire alcove that makes up this section occurs in the white layer that shows up in the video time after time. What the team was able to see does not support the probability of a passage as originally assumed.

We were very excited to learn that the water sample taken of what we thought was the rhodamine dye SWFWMD had introduced into the system last week was confirmed. The KUR dive team was able to find the dye for SWFWMD and illustrate that although the tunnel below the F well is definitely connected, it currently does not discharge to the head spring.

Thanks again to our volunteers, the staff at Weeki Wachee, the Florida State Park system and our sponsors for making the exploration possible.

NEXT: We will do another radio location at Helm's Deep and filming, in high definition, to that area of the cave.