Cave Diving on Merritts Mill Pond

by David Miner

Map to the Mill Pond

Merritts Mill Pond is located just outside Marianna, Florida in the Panhandle part of the state. It is easily accessed via I-10 from either the east or west.

Merritts Mill Pond is over four miles of crystal clear water, beautiful cypress trees, and steep hills lining its banks. The Pond’s beauty can only be measured in geological time periods because at times you feel as if you returned to the times of the dinosaurs when nature was untouched and unmarked by human existence. There are some homes on its banks and many other signs of human interaction, but Merritts Mill Pond is still an extremely beautiful place.

A man made damn at the southern end of the pond creates Merritts Mill Pond. Jackson Blue Spring, a first magnitude spring on the northern end of the pond, creates the lake effect from the thousands of gallons of water flowing out of the ground and being stopped by the damn. Sand, hydrilla, and cypress trees and stumps makeup the bottom of the pond and provide the vibrant white, green, and brown colors that contrast beautifully with the clear blue water.

The land that surrounds Jackson Blue Spring and the Mill Pond creates its watershed, which extends into Alabama. It is approximately fifty percent agriculture and fifty percent forest, clay hills, and limestone at or near the surface. All of the springs on the Mill Pond are tributary to the Chipola River. Unfortunately, due to the amount of agriculture in the area, water tests at Jackson Blue Spring and the Mill Pond confirm the second highest concentration of nitrates of any first magnitude spring in Florida. It is estimated that the water flowing out of Jackson Blue Spring has flowed underground for approximately 17 years. This means that if nitrate intrusion is reduced in the watershed area, that it will not have any impact on the Mill Pond for nearly 17 years! Nevertheless, the Mill Pond is a place of tranquil beauty and home to some of the best cave diving anywhere.

One of many Cypress trees in the Pond
The Pond

Cave diving on the Mill Pond involves the opportunity of diving up to four different cave systems: Jackson Blue, Hole in the Wall, Twin Cave, and Shangri-La. There are a couple of other recently found caves also on the Pond, such as Indian Washtub. Each cave system is unique, very sensitive, and diverse. Jackson Blue can be accessed by land with a stop at the local sheriffs office to sign in and pay the fee, but the others require a boat and a trip around the pond.

Cave Adventurers, a dive shop, operates directly on the Mill Pond. Cave Adventurers, operated by Edd Sorenson, offers everything you need for some great cave diving on the Mill Pond. Edd’s house backs up on the Mill Pond and his garage has been converted into a dive shop and air station. He has three pontoon boats for rent that are specifically set up for cave diving. The pontoon boats tie up to the extensive dock system behind Cave Adventurers making access to the different caves extremely easy and comfortable. Cave Adventurers offers air, nitrox, oxygen, and argon fills, rents double and single tanks, scooters, and has pontoon boats to get you to the dive site. They’ll even let you demo gear they have in the shop; just ask and they’ll set you up. They offer their friendship and hospitality to everyone and always make sure you have everything you need. Their knowledge of the cave systems is great, which is extremely valuable if you’re diving on the Mill Pond for the first time. To contact Cave Adventurers, go to

As mentioned, the caves on the Mill Pond are vastly different, each offering their own unique experience. Each cave offers something different but is also very sensitive and delicate. The following is a brief description of each cave system.

Jackson Blue

Jackson Blue entrance
Jackson Blue park in distance
Divers entering Jackson Blue
Divers in Jackson Blue
Twin cave dock
Twin cave entrance
Twin cave cavern

Jackson Blue is the most extensive cave system on the Mill Pond and as mentioned, is a large first magnitude spring, which is responsible for most of the clear water making up the pond. The spring basin is approximately 250 feet in diameter and is up to 20 feet deep. The cave entrance is approximately 8 feet high and 30 feet wide. There are thousands of feet of surveyed tunnel and a gold “main” line that runs all the way to the Banana room, which is around 4200 feet from the entrance. The cave walls are white limestone, and the water is crystal blue making for spectacular scenery. The cave water temperature is around 68 °F year round and visibility can easily be 100 feet or better. Maximum depth is around 90 feet.

Diving Jackson Blue can only be expressed in one word…fantastic. Whether swimming against the high flow and only seeing the first 500 to 1000 feet or scootering for thousands of feet deep into the cave, Jackson Blue has something for every cave diver. The beautiful white limestone walls, large breakdown, and large tunnels offer unsurpassed beauty and intrigue.

Map of Jackson Blue

Diving note: Before diving Jackson Blue for the first time, especially if you’re going to scooter, talk to Edd at Cave Adventurers about the system. Research the map and plan your dive accordingly. Edd knows this system well. Use their knowledge. Jackson Blue is a beautiful and sensitive cave system and will only remain that way if you know and dive within your limits and ability. Respect the cave system.

Hole in the Wall

Hole in the Wall is a beautiful cave system located approximately 800 yards down stream from Jackson Blue. Hole in the Wall is a large cave system with big tunnels and white limestone. There is an upstream and downstream, but this is a low-flow cave system and sometimes can even siphon. Just inside the cave entrance is a chimney that leads to the upstream and downstream tunnels. Visibility is usually much less than in Jackson Blue and depths range from 60 to 100 feet. You must have a boat to dive Hole in the Wall.

Hole in the Wall is home to a very rare cave species called the Georgia blind salamander. The salamander only resides in several areas of the cave system and is very sensitive to environmental change.

Map of Hole in the Wall

Diving note: Before diving Hole in the Wall, especially for the first time, talk to Edd at Cave Adventurers about the system. Due to the sensitivity of cave system and the presence of the rare blind salamander, it is recommended that you not dive this system unless you have completed at least 100 safe cave dives and have excellent buoyancy control. Scootering is not necessary due to the low-flow and is not recommended. Research the map and plan your dive accordingly. Hole in the Wall is a beautiful and sensitive cave system and will only remain that way if you know and dive within your limits and ability. Respect the cave system.

Twin Cave

Twin Cave is located approximately 300 yards downstream from Jackson Blue. Twin Cave is a low-flow system and is very silty, so excellent buoyancy control is a must. The cave water temperature is around 68 °F year round and maximum depth is around 105 feet. Visibility is usually very good. Twin Cave offers a couple fissure cracks, one at the entrance, that are beautiful and fun to drop through. Good technique is a must, as the cave is very unforgiving. You must have a boat to dive Twin Cave.

Twin Cave Map A

Twin Cave Map B


Shangri-La is approximately 200 yards downstream from Jackson Blue. There are several vents/cracks, but the main spring is a beautiful little cave around five feet deep at the base of the limestone bluff. Shangri-La is just large enough to squeeze into and generally considered a side mount dive. Visibility is excellent and there is slight flow. The cavern is beautiful and makes for a nice dive itself. Once through the entrance, the cavern drops to about 25 feet deep and is approximately 15 by 20 feet in size. The cavern is very silty and requires excellent buoyancy control to keep from reducing visibility.


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