Exploring the Weeki Wachee Underwater Cave System: The River Continues June 17

By Diane Bedard Posted on June 12, 2023

Have you heard about the giant cave system under the highway at the intersection of Cortez Blvd. and US 19 in Weeki Wachee? Did you ever wonder how it was found or if it goes elsewhere? How deep the water goes? How long the cavern system is? How it got here? How many people have been in it or something else about this natural wonder?

The opportunity to learn the answers will be available to guests at Weeki Wachee Springs on Saturday, June 17 from 7-9:30 pm. Join Karst Underwater Research team members, Dr. Andrew Pitkin, Brett Hemphill, & Matt Vinzant as they describe this incredible journey through one-of-a-kind pictures, videos, and stories. Hear how this incredible frontier was discovered, the amazing processes used to reduce risk of injury and death while cave diving, and what is to come for exploring the deepest natural freshwater cave system in Florida.

During this presentation, team divers will use the latest submerged cave exploration equipment to execute a photo shoot in the spring basin while audience members freely observe through the windows of the underwater theater.

Following the presentation, audience members will be invited to the Coral Room for an after-show meet and greet, where they can enjoy appetizers and beverages. Additional pictures, equipment, and Karst Underwater Research team members will be present during this portion of the event.

The cost is $28.52, including processing fees, and tickets are limited. Click here to order yours.

About the Weeki Wachee Underwater Cave System

Most people in Hernando County have heard about Twin Dees and the underwater cave system that is below Weeki Wachee Springs State Park. Brett Hemphill has been exploring it since 1998.

“I began exploring the Weeki Wachee cave system in 1998 with a permit issued by the State of Florida. We were looking at Twin Dees, or the Little Spring system, but the water pressure coming up through the entrance to the cave system from the main spring in Weeki Wachee prevented further exploration until 2007.”

weeki wachee cave system
Underwater exploration at Twin Dees. Image by Kirill Egorov.

Twin Dees and Little Spring

Twin Dees, aka Little Spring, on the east side of US 19, was initially explored by Paul Heinerth and Sheck Exley in the 1970s and 80s. In 1996, Jeff Petersen and Dave Miner of Karst Underwater Research discovered an enormous underground room and deep spring tunnel 300 feet below the surface, which they named Middle Earth and the Alph Tunnel respectively.

The system was not explored again until 2011, when Brett and Andrew Pitkin extended the Alph Tunnel to the southeast in the direction of Weeki Wachee. Continued effort over the next 3 years resulted in a large amount of new passage being explored, almost all of it deeper than 300 feet, and the eventual connection of the two systems on September 13th, 2014.

The main spring fracture, which provides the entrance to this enormous underground network of caves and tunnels was discovered in 1974, but with 117 million gallons of fresh water pushing through it from the Floridian Aquifer daily, it was not possible for divers to access the rest of Weeki Wachee’s underwater cavern system. (Water pressure in the cave entrance is measured to be approximately 250 cubic feet per second.)

Weeki Wachee area Drought allows Cave Exploration from 2007-2012

From 2007-2012, the Nature Coast experienced an extensive drought, causing the waterflow to be reduced significantly. This allowed 2-3 weeks each year to dive, map and continue exploring what is arguably the most amazing cave system in Florida.

weeki wachee underwater cave system
Karst Underwater Research divers descending into the Weeki Wachee Cave System. Image by Kirill Egorov.

“The entrance to the Weeki Wachee system is a fissure about the size of a standard door. The fissure is 75 feet below the surface. It is impossible for a standard dive rig to get through this opening, so we had to figure out some new ways of doing things. Fortunately, dive technology was improving at the same time as we were getting into Weeki Wachee,” Brett says. “The fissure is just large enough for a man to go through and then the passage descends to 170-190 feet below the surface before you get to the huge cavern room. We continue to dive and map the Weeki Wachee system and have mapped caverns to a depth of 429 feet!”

Preparing for Exploring the Weeki Wachee Underwater Cave System at Weeki Wachee Springs

When the team plans a dive, preparations start weeks in advance. It takes 25 people for a Karst Underwater Research dive. Seven safety divers are required from the surface to the Gauntlet – each is there in case a diver needs help with something. “There’s a 50/50 chance that something will go wrong, whether it’s equipment failure or human error, so we prepare to deal with it,” Brett explains.

brett hemphill
Brett Hemphill, of Karst Underwater Research, shows one of the 20 x 24 images by Kirill Egorov that will be raffled at the event. Image by Diane Bedard.

The Weeki Wachee underwater cave system is an ancient tie to prehistoric times on the Nature Coast. “I have found a dugong (prehistoric manatee) and small whale bones on my explorations here,” Brett shares. “There are fossilized microbes throughout many of the cave rooms.

Each dive offers the explorers about three hours of exploration time and ten hours of decompression management. The team at Karst consists of experienced divers who have a passion to improve their equipment and techniques with methodical testing.

diving in weeki wachee cave system
“There is nothing like the thrill of being the first human to see and experience these geological phenomena,” Brett explains. Image by Kirill Egorov

Karst Underwater Research has a Mission to Connect Us with Underground Water Resources

When asked why he risks his life, spending his own time and resources to explore underground caverns in Florida’s karst geography system, Brett responds that there is nothing like the thrill of being the first human to see and experience these geological phenomena. Then he becomes more serious. “I want people to understand that this is an important resource that is being degraded by the activity upland. I have seen a degradation in our springs that is significant. I want people to take ownership of these vast resources and value them,” he explains.

“The water is so pure… well… it was so pure… I noticed a change in 2006. Now I won’t drink directly from the spring. Three hundred feet down, the water is older and cleaner, but by the time it gets to the surface, it is mixed with water that has fertilizer chemicals and road runoff. It’s not the same.”

map of the weeki wachee cave system
Map of the Weeki Wachee Cave System by Karst Underwater Research.

Come to Weeki Wachee Springs State Park June 17 for “The River Continues” Program

The River Continues program offered at Weeki Wachee the evening of June 17, 2023, will cover the history of exploring the Weeki Wachee Underwater Cave System, the technology that allows Karst Underwater Research to continue to explore its depths, and the amazing natural phenomena that are part of this exploration.

It will also allow attendees to view actual divers in the spring filming with their equipment, see and purchase raffle tickets for amazing photos of the underground paradise that is below us, and meet and greet over hors d’ovres with the people who go below.

Don’t miss your chance to see a world that less than 25 people have visited – ever – at The River Continues program. Get your tickets here.

Additionally, Karst Underwater Research has chosen 10 unique images of the incredible Weeki Wachee cave system. These images have been professionally imprinted onto a 20″ X 30″ sheet of aluminum. Each image will have only 25 raffle tickets available. All images will be hand signed by the photographer, Kirill Egorov, on the evening of Saturday, June 17th at Weeki Wachee State Park. If you can’t make it but want to get raffle tickets for the beautiful photos being raffled, you can get raffle tickets for each aluminum print here.



Kathryn Obert says

I received this info on June 21…too late to participate

Florida's Original NatureCoaster™ says

I am unsure why you received the info so late. We published the story on June 12, and ran it as the featured story in our weekly e-zine on June 15. I am so sorry you missed it, as it was really interesting. They said that they may do it again and we will do our best to let you know.

Philip says

Interesting, informative article. Thanks.

Diane Luicana says

Will there be a way to see a recording of the June 17 presentation, we r snowbirds and not in Florida right now?

Florida's Original NatureCoaster™ says

There is no plan to record the presentation, but there may be a repeat, Diane

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