The Blue Abyss

Often talked about as one of the most spectacular cave dives a certified full cave diver might do in Mexico, the Blue Abyss is this amazingly HUGE cave room filled with salt water (below 50 feet) with depth ranging from about 15 feet all the way down to 240 feet. The nearest open-air entrance is over 2,500 feet away. Clarity of the water is unbelievable and is what gives Blue Abyss that stunning azure glow in our bright HID lights.

There are many ways to get to this room, but if you don't want to use scooters from the Nohoch nah Chich cenote, then the best way to do it is to go from Pet Cemetery cenote. We followed the Pet Cemetery cavern line then jumped to the main line which I think is initially part of "X"-line. From there we jumped onto Diaz line which took us within one short jump to Blue Abyss. We did this as a stage dive, not because of the distance but as an added safety precaution because of the depth we would encounter in the Abyss itself.

Diaz line has the "King Pong restriction" which although short, does tend to cause some divers more difficulty than one would expect. Even with a stage rig on my left hip, I had no trouble negotiating King Pong in either direction. In fact, I had so much fun doing it that if I were by myself I would've turned around and did it again... several times. I was thoroughly enjoying this dive!

Sometimes when I tell my friends what cave diving is like and describe cave passage restrictions like this in detail, they start looking at me like they're thinking "There's something fundamentally wrong with this guy." Whatever. Some people like watching basketball. Other people like visiting museums. I happen to love negotiating very small holes in a water-filled cave, 1000 feet from the nearest exit to air and sunlight.

After a long swim you arrive at Blue Abyss from a passageway at a shallow 15 feet or so. There is tannic fresh water there which somewhat limits visibility, but then you float over the precipice and ... whoa! The edge of the world drops off and there is this gorgeous blue water below you.

The dive to Blue Abyss is now in hot competition for being Best Dive of the Week -- it was way cool. As agreed before we started the dive, Bill and I were to partner together once we got to Blue Abyss since we were the only two using non-enriched air. (For those who don't understand, if you use an enriched oxygen mixture in your tanks a.k.a. "nitrox", it limits the depth you can dive. On regular air, you can "safely" dive to about 210 feet -- with nitrox, it is less depending on how much oxygen has been added.) Bill stated only that "we can go down deep, but if there is nothing more to see when I reach a certain depth, I'm going to stop descending." Seemed sensible to me, so that is what we did. So on arrival, all six of us went to different parts of this enormous sinkhole knowne as Blue Abyss. Bill and I sunk down to a depth of 117 feet at which point he signaled that was enough. Up we went slowly, back to the only entrance at the top.

Apparently the bright lights from all of us touring around was a spectacular sight for anyone who was on the upper levels. The cave is very, very dark and the walls not so reflective but with that many bright lights it apparently looked like a disco. I didn't get to see that spectacle from my point of view, or not exactly, because I was on the bottom level. Still, I couldn't help but be in awe of the sheer size of this place, and admire that there could be a place on land over 100 feet wide and 240 feet tall, all filled with water.

I would have been happy to stay longer, but everyone started heading out as if the dive had been called (I don't know if it actually was); we just started shuffling out slowly like the curtain had been closed and it was time to leave the theater.

Total dive time was 97 minutes and because of the time it took to drive to and from Pet Cemetery, it was the only dive we did today.

Blue Abyss is a "must dive" for any full cave diver. Five Stars. I will be back.

Footnotes

When I said I was diving on non-enriched air, it wasn't exactly true. I picked up my set of doubles from the standard air pile, not from the nitrox stack. Because I anticipated diving as deep as 200 feet, I decided to test the air with my nitrox tester "just to be sure" and GOOD THING I DID! Turns out that I had a 26% mix in there! It could have been a fatal error if I'd only assumed the tanks contained 21% and dove to 200 feet on that mix. According to the tables, the 26% is only safe to 138 feet on PO₂=1.4 or 156 feet on PO₂=1.6. I usually dive 1.6.

My right post regulator apparently has been going bad for some time now. My first clue was that it "hisses" (almost imperceptibly) when you first open the valve but it does it only for 15 seconds then never again the whole dive. However, my 2nd stage/inflator was leaking a little bit (only when 10 feet depth or shallower) and I'd always thought it was the inflator that was just being finicky. On my way in to Blue Abyss my 2nd stage was leaking ever so slightly more than it usually does and down to 19 feet. Well, after some diagnosis tonight I determined it was the 1st stage which is probably over-pressurizing the low pressure side. My 2nd stage/inflator worked fine on another 1st stage regulator. Tonight I'm going to swap out the questionable 1st stage and replace it with the one on my open water regulator, which I'd been using for my stage bottle. Today was the last day for stage dives so I don't need 3 regulators anymore this trip.

Even though Blue Abyss and cenote Pet Cemetery are part of Nohoch nah Chich (which is, effectively, part of Sistema Sac Aktun now) the cavern is accessed from the Dos Ojos main entrance from highway 307. It's a l-o-n-g way into the jungle on a rough road. I sat on both my towel and my wetsuit to cushion the bumpy ride, which probably saved my backbone from a trip to the chiropractor.

The fees to visit Pet Cemetery may be the highest of all cenotes in the region at a whopping 200 pesos. Fortunately with the current 14:1 exchange rate that means it is only about US $14. However that's still pricey compared to Grand Cenote (120 pesos), Dos Ojos (120 pesos) and Nohoch nah Chich (150 pesos). However the new facilities there are excellent and very cleanly maintained. They were still under construction when we visited today and the electric lights didn't work yet, but hey, the toilets flushed and they even had a high quality toilet paper in the stalls. Sure beats a hole in the floor of a palapa with four see-through walls and a can of sawdust!