Text by Brian Kakuk • Photos by Curt Bowen
As usual, it all started out with a phone call. “Hey Paul, how would you like a free cave diving trip to the Bahamas?” I asked. Paul Heinerth is well known in the cave and technical diving community and has more than his share of exploration and research expeditions to his credit. He quickly blurted out, “sure,” as if the offer was only good for a few seconds. Then I could hear the question churning in his head… “What do I have to do?” He knew he wasn’t going to get something for nothing, and I knew he had visions of sun, sand, and sea, so before he asked, I explained the offer.

A few months earlier, I had been cave diving with Jim Pickar on Great Abaco Island in the northern Bahamas. During a dive in one of the inland sinks, we had discovered some very old looking crocodile skulls and two huge land tortoise shells on the thick peat covered talus mound of the cave opening.
After sharing the discovery with my friends Michael and Nancy Albury, both local environmentalists and residents of Great Abaco, Nancy decided to notify Bahamian Officials and members of the scientific community. The response was one of great excitement, and thanks to Nancy, a joint project of Bahamian Environmentalists, Government Officials, and American divers was assembled.

I explained to Paul that the Bahamian Government had requested that I and two others come to Abaco to excavate, recover, and document the finds and that he and Curt Bowen from ADM were my choices. Curt would do his usual digital imaging magic and Paul would shoot the required video footage of the excavations and recoveries for the Bahamian Government.
Above: Crocodile Cave entrance pool

Right: Explorer Brian Kakuk emerges from the hydrogen sulfide layer
The plan was for me to head to Abaco a few days early for a meeting with Government Representatives, and Paul and Curt would fly out a few days later, after the permitting process and protocols had been put into place. Once I arrived in Marsh Harbor, Nancy set up the meeting in the conference room of Friends of the Environment, an Abaco based environmental not-for-profit organization, of which both she and her husband Michael were members and officers.

I was pleased to see the amount of interest and enthusiasm shown by the Bahamian representatives from many different governmental ministries. During the course of the meeting, it was decided that the find was significant enough to warrant an immediate recovery effort and Archaeological Research Permits were granted by Dr. Keith Tinker, Director of the Bahamas National Museum - Antiquities, Monuments and Museums Corp. (AMMC). Excavation and recovery plans were organized via e-mail and telephone with the guidance of Richard Franz, a Paleontologist from the Florida Museum of Natural History, considered an expert in this area. Paul and Curt were also notified and they flew to Marsh Harbor two days later with their equipment to do the still and video documentation of the excavation and recovery efforts.

Sawmill Sink
The sinkhole or “blue hole” as they are known in the Bahamas, is located within the quiet, rocky pine forest in the interior of the island, a few miles south of Marsh Harbor. Locally known as Sawmill Sink, this remote inland sinkhole was first discovered by the Owens Illinois Pulpwood Co. in the early 1900’s. The company had used the site as a fresh water source for the locomotives that hauled the Bahamian pine trees out of the “bush,” where it was later broken down into pulp. After the closing of the mill, the site was quickly reclaimed by the pine forest, and the site was only used as a swimming hole until cave divers from the United States began to trickle into the Bahamas. Some of these divers included George Irvine, Dan Malone, and Fred Davis.
Left: Veteran explorer Paul Heinerth prepares for a dive with his Cis Lunar rebreather

Below: Cover Photo, Brian Kakuk measures a crocodile skull (C1)
The cave associated with this sink is an interesting mix of solutional passages, eroded speleothems, and unique, deep mud banks that show evidence of drying and cracking during ancient low sea levels, the latter item being found as deep as 170 feet in some parts of the system.

The water chemistry within the system is fairly common, though somewhat exaggerated for a Bahamian Blue Hole. A fresh water lens sits atop the denser seawater that permeates the porous limestone of the island. Heavy organic input, in the form of tree leaves and branches has created an aggressive and very stinky hydrogen sulfide (H2s) zone between the depths of 30 and 37 feet. Within the H2s is an active layer of bacteria, which consumes the foul smelling gas. This biological process removes most of the oxygen from the water in this zone and below. It is the lack of oxygen within the thick organic peat of the talus mound that protected, and to a certain extent, preserved the bones and shells found by the divers.

Recovery methods and equipment
During the initial dives at Sawmill, I quickly realized that any time spent on the peat talus mound would need to be done on rebreathers if the recovery team was to maintain any decent visibility. Curt and I brought Megalodon CCR’s, while Paul brought his “Cadillac” Cis-Lunar Mk-5P CCR. Medical grade oxygen was ordered through a local Marsh Harbor distributor, while the Sofnolime 8-12 grade was shipped to Abaco from a recently completed research project on Long Island, Bahamas.

Air diluent was sponsored by Mr. Keith Rodgers of the Marsh Harbor based “Dive Abaco,” and this air was also used as drive gas for the team’s Jetsam Technologies baby booster pump, allowing us to do all of our fills right out of the office of Friends of the Environment.

The Actual work sites varied in depth from 47 feet, up on the talus mound, where three tortoises were found (two males and one female), to 108 feet near the base of the mound where most of the crocodile remains were located.

Prior to excavation, tags were placed on the guideline as close to each site as possible. Each tag indicated what the item was thought to be, and its depth in relation to the guideline, so that the team could find the items more readily. Tortoises were labeled T-1 through T-3, in the order they were found, while the croc remains were labeled C-1 through C-8 (later the C category would be extended to over 14 sites).
As per Richard Franz’ instructions, a two meter long by one meter wide PVC grid was fabricated and subdivided into half meter increments with cave line. The grid was then placed over each site as it was photographed and worked. The grid was “pegged” in place on the steep peat mound by two PVC rods that were carefully pushed down into the peat. The rods would allow the grid to be removed and replaced without losing the exact location of each site. Curt and Paul photographed all of the sites with the items in-situ, prior to any material being disturbed. After the photography was completed, the grid was placed on first tortoise site at a depth of 57 feet just below the H2s layer.

The first item removed was the crocodile skull C-6 (see graphic for locations). Crocodile skull C-6 was actually found while photo documenting the grid area around tortoise T-1, on the peat talus mound. While waiting for the sediment to settle for a photograph of T-1, I inadvertently placed my hand down in the sediment within the lower part of the grid. As my hand slid into the peat, I felt a sharp bite on my fingers and quickly pulled my hand out of the goo. I moved a small amount of peat where my hand had been, and quickly realized that I had just been bitten by what could possibly be a 3,000-year-old crocodile skull!

The ten-inch long C-6 was carefully uncovered within the grid, while keeping an eye out for other small bones from the specimen. It was slowly removed from the sediment and then placed in an appropriate sized Tupperware container while still in the low oxygen water environment of the recovery site. The skull was then taken to the surface where Nancy took possession.

The next items removed were tortoises T-1 and T- 2. These required a bit more planning due to the large containers, and the weight of the water that would be in the container preserving the shells. The task loading involved with juggling the containers, cameras, lights, grids, and measuring devices was, at best, intense in the near zero visibility of the peat mound. Regardless, after three days of diving, digging, measuring, mapping, photographing, and hauling, the team had two ancient tortoises, one crocodile skull and several bags of associated skeletal remains safely on the surface.
Above Left: Brain Kakuk emerges with smiles after a discovery of a third tortoise shell
Left: Bahamas officials and the U.S. dive team pose with the first ever discovery of a Bahamian tortoise
Throughout the 10-day project, many more sites were found around the circumference of the blue hole. The count is now up to 14 crocodiles and 3 tortoises. There will undoubtedly be more. This project has raised more questions than it has answered. Was Sawmill Sink a trap for the animals of that time period, much like the La Brea Tar Pits of California? How long were these animals in this area? Are all of the sites within Sawmill Sink roughly from the same era? Were the tortoises dragged into the sink by the crocs? Are the tortoises possibly a new species yet unknown to science? The list goes on and on.

Sawmill Sink has since been declared a closed archaeological area, and diving activities are conducted under a strict permitting process through the AMMC. It is the hope of both Dr. Tinker and Richard Franz that this find will lead to more formal and continued research at this site. The peat on the mound is so deep in some areas, that the team has been unable to find the hard bottom of the talus mound. Who knows what kind of archaeological treasures will be found even deeper in the stinky goo of Sawmill Sink?

The team would like to thank the following participants

• Dr. Keith Tinker, Director of the Bahamas National Museum and the Antiquities, Monuments, and Museums Corp. (AMMC)
• Mr. Michael Braynen, Director of the Bahamas Department of Fisheries
• Dr. Livingston Marshall, Science Advisor to Prime Minister of the Bahamas
• Mr. David Knowles representing the Bahamas Department of Agriculture
• Mrs. Lynn Gape, Director of Education and Public Relations for the Bahamas National Trust
• Mrs. Anita Knowles, representing Friends of the Environment
• Mrs. Nancy Albury, Project Supervisor
• Mr. Michael Albury, Council Member of the Bahamas National Trust

Special thanks go to:
Michael and Nancy Albury for financial support and for opening their home to the dive team; Friends of the Environment for letting the team turn their conference room into a dive shop; Keith Rogers of Dive Abaco for donating all of the compressed air to support the diving operations; Richard Franz for his guidance on the excavation, recovery, and preservation methods; Dr. Keith Tinker for having the insight to make this project happen on such short notice and the financial support of the AMMC.

For more information on the Crocodile Cave Project, contact Brian Kakuk at:
Below: The moon rises above the pine forest as photographer Curt Bowen illuminates the entrance to Crocodile Cave. This timed light exposure creates a unique digital painting of one of mother natures wonders.