Sistema Ox Bel Ha: Quintana Roo's newest giant

By Christophe Le Maillot

This is a short description of the 1998 to mid-1999 exploration project of the Ox Bel Ha Cave system (a connection between Sistema "Del Mar" and "Esmeralda").  Using different configurations, approaches, and techniques, we patiently discovered what potentially could be the third largest underwater cave in the World.


A cave of this proportion offers a variety of distinct features.

-A shallow portion (25 to 34 ft) is encountered from the main Cenote (Del Mar) up to 5000 ft upstream in a W/NW heading. The very swampy surrounding gives the cave a black coloring, very similar to Sistema Naharon. Various decoration can be observed throughout the cave. Shallower rooms seems to present more features. Eight different cenotes are scattered over this large area. A light flow can be felt at all times.


-Very large tunnels and huge chambers in the most western

direction before Cenote Canales. The average depth is 40 ft and the deepest section (Orion) is 47 ft. The halocline is found between 42 and 45 feet. Flow is always present. There's a beautiful Cenote 9000 ft upstream from the main entrance: La Familia.


-A northern lead with a wide tunnel and complex side passages.  Many breakdown areas and tanic domes (blind cave fishes and isopods are often observed there) made for an interresting dive.  The halocline is observed at 40 ft. The maximum depth is 55 feet.


-Three connections to the ocean via similar but different routes. Going straight East, this complicated downstream becomes shallower closer to the sea. The flow gets strong towards the exits. Sidemount configuration is sometimes necessary to go through several restricted parts. The bottom composition turns gradually to sand. Seafans, coconuts, and shells are a constant reminder of the cave's proximity to the ocean. The fresh and salt water only mixes near the surface (about 8 ft). All exits are located approximately 400 ft away from one another.  Snappers and Grunts are found in large numbers in the short cavern zones of the exit cracks. Tarpons were encountered a thousand feet inside the cave (always a scary surprise).


-Canyon areas past Cenote Esmeralda where the depth ranges between 50 to 80 feet. These deeper salt water passages are highly decorated and contain numerous fossilized sponges. The tunnels are big, with an average width of 40 ft.


A condensed exploration overview:


June 1998:


After a quick reconnaissance dive on the 3rd, we travel back the next day to enter Cenote Del Mar. The objective was to re-survey the existing line from previous French and American projects. These projects were led by Steve Keane, Tamara Kendell, and Christian Thomas. After completing the objective, Bernie and I laid 5,500 ft going straight east towards the ocean. This downstream section is characterized by narrow passages and strong flow (lines: Al Mar, E Gate, Cabanas, and Mosquitia). Diving S/SW from the Main Entrance (Cenotes Del Mar), a 3,000 ft loop was added (lines: Labyrinth, Lab Conecter, L Line). Working around the nearby Cenote Mangrove and Tarpon, 3,500 ft was laid due W (Kite and All Black lines). From existing lines (names Wassy and Wussy), in a N/W direction, we squeezed this time with our sidemount configuration through the small Coconut Drive and D.O.M. Sections for 2,000 ft of new lines.


No. of dives: 12

Total Bottom Time: 2085 minutes

Total line surveyed: 15,500 ft.

Total line laid: 12,150 ft.

Explorers: Bernie Birnbach, Bil Philipps, Christophe Le Maillot


July 1998:


We were excited by the previous exploration. We decided to focus on exploring further upstream. The cave in that area seemed to be the most promising for exploration. After 5 dives, we laid more than 10,000 ft. To the NW, we added to the map the following lines: KFC, Magic, Aves, Arbol and one Cenote: La Meza. The main passage turned west, to run 2,150 ft (Low Land line) to the beautiful Cenote La Familia. On later dives, the team progressed north from the Wassy Line. We encountered a shallow and decorated cave (DOM 2) at first, which extended after 1,000 ft to a deeper section (Rimet). The halocline was visible at 38 ft. During another two dives, we joined Bernie's Aves line with Rimet (Der Konnector: 900 ft), and found a lead going SE (Syphon Norte). Towards the end of the month, and during five long dives, Daniel Riordan helped us in pushing the Rimet section for another 7,400 ft. The end of the line is now 10,046 ft from Main Entrance.


No. of dives: 15

Total Bottom Time: 3407 minutes

Total line laid: 23,786 ft

Longest penetration from Main Entrance: 10, 046 ft

New Cenotes: La Meza, Victoria, De La Familia

Explorers: Bernie Birnbach, Daniel Riordan, Christophe Le Maillot


August 1998:


The objective for this hot summer month was to connect the cave to the ocean. From the shore, we observed four gushing fresh water boils coming out in the ocean from the direction of the downstream cave. The gushing water boils were separated from one another by a distance of approximately 400 ft. The first visible out-flow was located just a front of Cabanas Tulum. The existing eastern line from Cenote Del Mar: E Gate and Al Mar were going towards the sea but the strong flow made it challenging for the team to attempt a connection dive from inside the cave. The team divided into two diving groups. Both team entered the same entrance from the ocean side while following different tunnels. The flow was quite strong. Both teams finally connected the two side of the cave together at two different spots after only 600 ft (the E Gate line - exit 1). The other exits were eventually connected with the main cave: #2 after 550 ft of narrow passages; and #3 a few days later with a smaller entrance but a better defined tunnel to Al Mar section. However, Exit 4 was too restricted to squeeze further in. Only a few dives upstream were made during the remainder of the month, adding "Ball Park" to the end of "Lowlands" for another 2,450 ft (still going big W/NW), and another off shoot tunnel of 1,400 ft (Sickman's Passage) to the main "Rimet" Section.


No. of dives: 10

Total Bottom Time: 1270 minutes

Total line laid: 9,190 ft

Explorers: Bernie Birnbach, Daniel Riordan, Christophe Le Maillot, Fred Devos


September and October 1998:


The general objective was to continue with the exploration of the enormous "Ballpark" and "Rimet" sections. We used set-up dives to avoid losing too much time going through the first restricted part of the system with too much equipment. After a couple of failed attempts, we managed to extend "Ballpark" by 2,000 ft and finding a small cenote (Luz). On 6/10, we returned adding Orion to the chart for another 3,000 ft, and setting our personal penetration record to 14,000.


NNo. of dives: 6

Total bottom time: 1343 minutes

Total line laid: 5,000 ft

Longest penetration from Main Entrance: 14,000 ft

Explorers: Bernie Birnbach, Christophe Le Maillot


November and December 1998:


We discovered two interresting sections ("Blind wall" and "Black hole") from the main upstream tunnel. These two sections were running SW/S/SE for a total lenght of 2,800 ft out of the "Ballpark" line. Another line: "El Tucan" was laid from "Rimet" . This line ran SE..


No. of dives: 2

Total Bottom Time: 715 minutes

Total line laid: 4,500 ft

Explorers: Bernie Birnbach and Christophe Le Maillot

Total surveyed passage for the year: 58,000 ft


January, February and March 1999


A better land survey and a closer look at various aerial pictures, made the team realized the proximity of Sistema Del Mar with Sistema Esmeralda. In fact, Cenote "Luz" could potentially be part of "Canales". Cenote Canales is a long strip of interconnecting sink holes. We thought that from the "Orion" line we might be able to eventually connect to Sistema Esmeralda. Unfortunately, we were several times unsuccesful from this side of the cave. However on March 13th, we headed instead for the "Ball Park" section. Here, we found ourselves at a depth of 55 ft exploring 350 ft of beautiful cave. It opened up to a shallower breakdown area. We swam further in against what appeared to be a very encouraging flow. We battled restrictions for another 600 ft carefully negotiating unstable cave. We finally found afront of us an unfamiliar line (Paso de Lagarto). This line was laid several month before from Cenote Esmeralda. We finally accomplished the connection between Sistema Del Mar and Sistema Esmerealda. The connection between the two systems became Sistema Ox Bel Ha.  We surveyed back to the main line. On the same dive, another 1,100 ft of tunnel was discovered from the end of "Ball Park".


No. of dives: 7

Total Bottom Time: 1459 minutes

Total line laid: 4,300 ft

Explorers Del Mar: Bernie Birnbach, Christophe Le Maillot,

Explorers Esmeralda: Sam Meacham, Bil Phillipps, Fred Devos, Daniel Riordan

Total Length of Ox Bel Ha to date: 101,000



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