Trip report Sian Ka’an March 13 to 25 Project Report - June , 2006 update

13/06/06

Team: Fred Devos, Daniel Riordan, Per Thomsen, Nathan Campbell & Johanna Rodriguez.

Dive site: South of Tulum on the road to Punta Allen. This is the north end of the Sian Ka’an biosphere. Entrance of the cave is opposite a little Mayan ruin. There’s a circular collapse lying at a depth of 20 feet in the murky water of Laguna Caapechen. Previous explorers have named it entrada “Manatee”. The cave starts due west at a Depth of 42 feet.

Previous exploration: A team of French divers lead by Christian Thomas was the first to explore the initial 1,200ft of cave passage in 2001. During the February 2006 OBH project, further investigation was conducted by Fred Devos, Per Thomsen, Andrea Marassich and Jarrod Jablonski. They explored, surveyed and videoed a total of 3,594ft of new cave. During the following month of March, April & May more exploration & documentation was carried out by the Mexico Cave Exploration Project. The cave has a total length so far of 19,999ft.

Conditions: The water condition generally improves at 20ft from murky surface water to clear 100ft + viz. The visibility in the cave is normally good on the way in. There’s heavy percolation all the time. This is mainly organic silt but clay is visible too. There is a unique gelatinous substance in the salt-water hanging down from the ceiling or ledges of the cave. This hasn’t been observed before in other caves in the area. The strange substance looks like fake speleothems (there’s good documentation of it from the Feb and May project). The flow seems to come from the SW/W & rarely from the NW. The flow can be v substantial in the first part of the cave. It is sometimes necessary to kick in while scootering in on full pitch. Water temp is 79F except in “Silica Dome” where water temp is 81F at 40ft. The depth of the halocline changes rapidly over a few thousand feet from 48ft near the entrance to 53ft at 2000ft to 61ft at 6000ft.

Access: The Visitor Center (Centro de Visitantes) in the Sian Ka’an Biosphere is the perfect set up for base camp. There’s a small dock facing Laguna Caapechen. The boat ride to entrada Manatee is 15 minutes. Accommodation is basic but convenient & clean.

Logistics: 20 stages w/EANx32, 15 stages w/ 30/30, 9 dls w/EANx 32, 6x33amp scooters, 2 x extra 33amp battery packs & generator.

Objectives:

Check on safeties that were left in the cave at 4K from last project
Add 2 other safeties at 7K for continuing exploration of the end of “Shells”
Cut T to “Fracture South” back
Photograph section of cave from 4K to 7K.

Summary of results:

A safety at 4K needed to be worked on. Regulator was full of silt and needed adjustment.
Safeties dropped OK at 7K
Cut T ok under heavy silt. This is a particularly challenging part of the cave with silt, halocline and narrow passageway.
Photographed area of cave from 4K to “Silica Dome” & “Gandalf” area. Heavy percolation has made photo shoot challenging.

Possible follow up:

Extend the exploration of the end of line at 4,579 feet. There’s a big NW lead with inviting flow there.
Check on the dome areas for SW leads
Probe the many N leads
Replace French line at the right of first T junction.

Other comments/observation: The wind was blowing from the East. Surface was choppy. Little flow felt at the entrance. Is this related to wind direction? There’s a big school of dog and cubera snappers patrolling the sunken sink hole. Remoras are part of the pack too.

Acknowledgements: Sam Meacham, Christian Thomas and the team of French explorers, Jim Coke, Ecocolors, ragatours, Amigos de Sian Ka’an, The Nature Conservancy.

Equipment and Survey: 3stages and 2 scooters per diver (1 x 33amp + 1x 18amp). The first stage was kept in the cave with 2000psi of gas. It took 25 minutes to scooter to the end of “French Flow 2”. The 18amp scooter was use as a back up. Survey was done on the way in. This is a better method of survey as there’s plenty of gas for exit and no unnecessary time pressure.

Dive log:

# 1 Time in: 12h00 / time out 12h55
Total run time: 55 minutes / Max Depth: 55 feet / Av Depth: 45 feet
Divers: Fred & Chris

# 2 Time in: 13h15 / time out 15h35
Total run time: 145 minutes / Max Depth: 101 feet / Av Depth: 50 feet
Total exploration day: 1,450ft
Divers: Fred & Chris

Line’s name: “French Flow 3” & “North Hope”

24/03/06

Team: Alex Alvarez, Fred Devos & Chris Le Maillot.

Dive site: South of Tulum on the road to Punta Allen. This is the north end of the Sian Ka’an biosphere. Entrance of the cave is near a little Mayan ruin. There’s a circular collapse laying at about 20’ under the murky water of the laguna. Previous explorers have named it cenote “manatee”. The cave starts due west.

Previous exploration:
Fred & Chris extended penetration to 4,579feet on March 23.
Conditions: the water condition improves at 20ft from the murky Laguna water to clear 100ft + viz. The visibility in the cave is generally good on the way in especially for the front man. There’s heavy percolation. Strange organic goo covers a lot of the cave wall. It stretches considerably under its own weight and creates fake speleothems. The flow seems to come from the SW/W&NW. The flow can be v substantial for the first hundred feet near the entrance. The water temp is warmer in the fresh water: 79F. The halocline sits at 55ft.

Access: Eco lodge EcoColors 10kms past the Sian Ka’an Arco provides ideal base camp. There’s a 15 minutes boat ride from the dock to Cenote Manatee.

Logistics: 14 stages w/EANx32, 5 dls w/EANx 32, 2x33amp scooters, 2x18amp scooters, 4 extra 33amp battery packs & generator.

Objectives:

Continue exploration from the end of the line
Remove the rest of the French line at the right of first T

Summary of results: 1. Additional 1,443 feet of line added to ‘North hope”. The line stopped in a huge chamber heading W/NW with flow.
                                  2. Successful removal of remaining French line.
                                   3. Additional 300ft added in a bedding plane with halocline near bottom floor. There’s lots of organic sediment all around. Cave still goes NE. Barely noticeable flow.
                                   4. First T cut back.

Possible follow up: 1. Extend the exploration of the end of line at 6,022 feet. There’s a big chamber with many speleothems there.
                                2. Check the SW leads. There is noticeable flow coming from the SW.
                                3. Probe the many N leads

Other comments/observation: 1.The wind was blowing from the North. Water surface was calm. Strong flow at the entrance.
2. There’s a white dome 5,200 feet in at a depth of 35ft with no percolation and a thin white dusting over layer of red clay. The water temp is 81F.

Acknowledgements: Sam Meacham, Christian Thomas and the team of French explorers, Jim Coke, Ecocolors, ragatours, Amigos de Sian Ka’an, The Nature Conservancy.

Equipment and Survey: 3stages and 2 scooters per diver (1 x 33amp + 1x 18amp). It took 32 minutes to scooter to the end of “North Hope”. The 18amp scooter was use as a back up. Survey was done on the way in. This is a better method of survey as there’s plenty of gas for exit and no unnecessary time pressure.

Dive log:

# 1 Time in: 11h30 / time out 14h15
Total run time: 165 minutes / Max Depth: 70 feet / Av Depth: 57 feet
Total exploration: 1,443 feet
Divers: Fred & Chris

# 2 Time in: 14h45 / time out 16h17
Total run time: 92 minutes / Max Depth: 50 feet / Av Depth: 40 feet
Total exploration: 300 feet
Total survey: 500 feet
Divers: Alex, Fred & Chris

25/03/06

Team: Luca Magheli, Gianmario Rocca, Fred Devos & Chris Le Maillot

Dive site: South of Tulum on the road to Punta Allen. This is the north end of the Sian Ka’an biosphere. Entrance of the cave near a little Mayan ruin. There’s a circular collapse lying at about 20 feet under the murky water of the laguna. Previous explorers have named it cenote “manatee”. The cave starts due west at a Depth of 42 feet.

Previous exploration: A team of French divers with Christian Thomas were the first to explore the initial 1,200ft of cave passage several years ago. During the February 2006 OBH project; further investigation was conducted by Fred Devos, Per Thomsen, Andrea Marassich and Jarrod Jablonski. They explored and video a total of 3,594ft of new cave.

Conditions: the water condition improves at 20ft from the murky Laguna water to clear 100ft + viz. The visibility in the cave is generally good on the way in especially for the front man. There’s heavy percolation. Strange organic goo covers a lot of the cave wall. It stretches considerably under its own weight and creates fake speleothems. The flow seems to come from the SW/W&NW. The flow can be v substantial for the first hundred feet near the entrance. The water temp is warmer in the fresh water: 79F. The halocline sits at 55ft.

Access: Eco lodge EcoColors 10kms past the Sian Ka’an Arco provides ideal base camp. There’s a 15 minutes boat ride from the dock to Cenote Manatee.

Logistics: 14 stages w/EANx32, 5 dls w/EANx 32, 2x33amp scooters, 2x18amp scooters, 4 extra 33amp battery packs & generator.

Objectives:

Continue exploration to the SW this time.
Further exploration near the entrance of the cave to the North.

Summary of results:

After a 35 minutes scooter ride, the team pushed SW a couple of station after the end of “North Hope” (laid 23/03). An additional 1,550ft of cave was discovered and surveyed.
A second dive was conducted going N after a quick scooter ride on the ML (12 minutes). An additional 450 ft of line was laid in that direction. There’s a breakdown area that blocks anymore progress N. As a result, the cave was swinging to the SE and will probably loop back to ML.

Possible follow up:

The end of the line laid today (Paso del Sur) is at 70ft and can still be pushed south. However, this is obviously not the main conduit.
There is big leads from “Paso del Sur” going SW/W that were missed during the 25/03 dive. This needs more investigation.
A SE lead from “Paso del Sur” was observed and needs to be checked soon.

Other comments/observation: The wind was blowing from the North again. Surface water conditions were calm. The flow was strong at the entrance. Is this re-enforcing the theory that wind direction is relevant to flow?

Visibility in the entrance pool was 5ft. This is another change from the previous days of diving. The visibility cleared up at a depth of 35ft.

Bottom timer recorded a water temp of 81F throughout the dive.

The cave seems to be more open to the SW. The cave is large in some areas.

Apart from the heavy layer of organic matters still covering the entire cave, the limestone underneath it is bleached white and solid.

After hitting the ceiling and clearing it from organic sediment, the diver’s bubbles makes the white limestone more apparent. This is like having a marked trail on the roof of the cave.

Acknowledgements: Sam Meacham, Christian Thomas and the team of French explorers, Jim Coke, Ecocolors, ragatours and Aldo, Amigos de Sian Ka’an, The Nature Conservancy.

Equipment and Survey: 3stages and 2 scooters per diver (1 x 33amp + 1x 18amp). The first stage was kept in the cave with 2000psi of gas. The 18amp scooter was use as a back up. Survey was done on the way in. This is a better method of survey as there’s plenty of gas for exit and no unnecessary time pressure.

Dive log:

# 1 Time in: 11h00 / time out 14h25
Total run time: 205 minutes / Max Depth: 70 feet / Av Depth: 58 feet
Line’s name: “Paso del Sur”

Divers: Fred & Chris

# 2 Time in: 14h45 / time out 16h17
Total run time: 92 minutes / Max Depth: 50 feet / Av Depth: 42 feet
Total exploration day: 1,900ft
Divers: Luca, Fred & Chris
Line’s name: “Blanmange”