Category — Car Wash

The advantages of a closed circuit rebreather in a shallow cave.

I have to admit that I recently neglected rebreather diving and instead spend most of my time off sidemounting. I pretty much used my rebreather for deep diving only. But recently that changed, I finished crossover training on the Poseidon Cis Luna Mk6 and right after that was with Howard, aka Scubadadmiami for a week of CCR Cave diving. And I am hooked on CCRs again.

The Mk6 exceeded my expectations but this is not what this article is about. What I want to share here is my recent experience diving Ponderosa, Taj Maha, Nohoch Nah Chich, Grand Cenote, Carwash and Naharon. Generally all the dive sites have an average depth of about 30ft and Nohoch even being shallower with Naharon being the exception at 60ft.

In many posts on CCR forums, the Mexican caves are described as CCR “unfriendly” and honestly I do not understand why? Our recent experience illustrated that CCRs can be used effectively in these caves and enabled us to get to know whole sections of systems in only one dive.

Normally when I guide people open circuit I choose a cenote and then guide two dives to the most famous or pretty parts of the system. The dives are usually turned either on time or gas which results in returning to open water. The option to recalculate thirds does exist, however, my opinion is that it should be reserved for experienced divers with experience in the particular system. When divers elect to recalculate thirds, eventually the gas reserve becomes to small to be safe.

The advantage of the CCR is that you have a bail out radius which enables you to spend as much time as the scrubber will allow, normally about 3 hours which is a huge opportunity here in the Riviera Maya.

The cave systems here are like Swiss cheese with many different side tunnels and passages. They are also very shallow. These two characteristics combine to create a situation where divers have a very long range on an 80cuft cylinder. Depending on you gas consumption while bailing out and conservatism factor you want to build in you will have a radius of at least 40min in most places. There are other benefits worth mentioning:

1. Once you come of the frequent traveled passages you will often encounter quiet significant amount of percolation that can seriously affect the visibility.
2. Thinking about the lost line or lost diver scenario, imagine how your chance of survival or the chance of finding your dive partner will increase with an hours long supply of breathing gas.
3. How many accident reports have we seen that speak about people drowning only minutes away from an exit, what would have happened if they would have been on a rebreather.
4. Taking pictures on the way, on a CCR you penetration distance is not going to change because you stop at a place to take some pictures or simply take a brake.
5. Think about a reverse block way back in a cave, how much more relaxed are you going to be, knowing you can stay there fro hours.
6. No time or gas pressure to go to a certain part in the cave and therefore reduced chance of pushing limits due to being goal oriented.
7. And many more

Of course this is a double edged sword and there are as well some negative aspects:

1. Buoyancy is definitely more difficult.
2. It is the perfect tool to bring people that where before limited by their air consumption far into the overhead environment and by that outside of their comfort and experience zone.
3. With most units together with the bail out your overall size in the water column is bigger and therefore you need more effort to travel.
4. Many ups and downs consume Oxygen and Diluent volume.
5. Getting overconfident due to the feeling of having unlimited gas supply.
6. Proper bail out gas and volume is never an issue until it becomes an issue.
7. And many more

To have a real advantage with the CCR we have to change the way we dive in the cave. Instead of using it to go for that record braking long distance penetration why not stay closer to the entrance but get to know all the lines that are in that area.

For example, at Naharon we dove up the main line and did the Jump towards the double domes. We swam up that line until we reached 40min, or bail out distance. On the way we stopped several times to take pictures and simply stopped the timer while we did not go further in the cave. On the way we marked the double set of line arrows that mark the jump towards south western sac be. On our return we arrived back at the arrows and new that from this point on we had 30min for further penetration so now we did the jump and enjoyed the really unreal beautiful sac be section.

On the way there we pass yet another set of double arrows marking the jump that lead down towards Cenote Mayan Blue and again marked it. We continued in the sac be tunnel until we had reached 30min from the jump and turned our dive. On the way back we stopped again a couple of times to take pictures. We didn’t even have to take care about the time since we were well inside our bail out range.

As we arrived back at the Arrows we decided to make yet another jump and check out the line that leads towards Mayan Blue. After some time we turned from there and now did the entire return trip back to Cenote Naharon.

As you can see, we did in one dive what, in conventional OC cave diving style would need three dives. We had an average depth of close to 60ft with a 180min runtime, me carrying an 80cuf and Howard 2 40cuf bail out tanks.

Another example would be Carwash where we could use Lukes Hope to restart the 40min bail out range and therefore had plenty of time to visit the room of tears and all the different Ts in the back. On the way out we did the jump that leads to the back of the room and stayed there for like 30min just doing pictures and enjoying the decorations.

In Grand cenote we went down to the Cuza Nah Loop and could restart the 40 min each time we past a cenote which was awesome since this gave us the possibility to do the jump at the mid way of the loop and take our time while swimming down that line again taking pictures and having a great time. On the way back we continued the loop on the other way since we were still easy inside our bail out range.
And the same was done in all the other places.

All in all I really enjoyed this week especially the possibility to visit lines I have not been too in a long time. I really love to do complex navigation, see different lines and go back and forth and all around.

Another bonus, so to speak, was to get more experience on the Kiss Classic which I really start to like more and more for its simplicity, the 20min prep in the morning and the 5min tear down in the evening, the free chest, constant O2 flow which facilitates buoyancy and the general possibility to keep the same configuration than with a set of doubles.

For Howard it was great too because he really got to know quiet a bit of each system we dove at, although he only did ONE dive there.

Considering all of the above, I would call the caves here perfectly suited for CCR diving if you bring the right set of skills, a good attitude and some creativity to the table.

Of course there are always people that say OC backmount is the only way to go and others believe that OC sidemount is the best, then there are some that believe in multiple stages or scooters or I don’t know what else; Me, I think it all has its use and its just what you do with it that makes it valuable. Try to get the most advantages out of whatever equipment you use and try to work with the right tool for the job!

Keep the loop closed but your mind open!!!

Patrick

Editor’s Note: I want to apologize to my readers.  I posted this story in the middle of the night with some errors.  Particularly, I got my sac rate calculations wrong.  I checked my notes today and discovered I used more gas then I first thought and I checked my X1 average depth and realized I was using a deeper depth then it recorded.  — Hans

When I arrived in Mexico last winter, Steve Bogaerts and I developed a rough plan for my training. The training would include: Basic Sidemount, Advanced Sidemount, Cave Survey, Cave DPV, Stage/Multi-stage and CCR Hypoxic Trimix.  As of today, the only class I have left is stage/multi-stage.

We planned to spread the training over the course of a year and to pace it based on my progress.  My progress would be reflective of the number of dives I complete and the focus I put on practicing.  I am glad that I am a little ahead of schedule.  Today, I finished my 12th training day with Steve and we completed Cave DPV.

The Cave DPV course was a lot of fun.  I wasn’t as difficult or as stressful as some of the other courses, such as Advanced Sidemount.  Riding a scooter is like flying.  It is super cool to zip through the cave.

The DPV course took three days. The first day started with three hours of lecture.  We discussed:

• Why to use a scooter
• Safety issues
• Gas planning
• Emergency procedures
• Team dive execution
• Staging the scooter
• Choosing a scooter
• Batteries
• Charging
• Conservation
• And a host of other topics.

After the lecture, we broken down Steve’s Silent Submersion UV-18 DPV and prepped it for diving.  The prep went something like this:

1. Check the voltage of each battery. (13+ volts)
2. Check the voltage of the combined batteries. (26 volts)
3. Inspect and clean the o-ring and sealing surfaces on the motor end of the scooter.
4. Inspect the motor compartment through the window.
5. Ensure the cap is secure on the motor compartment.
6. Attach the battery.
7. Check to make sure the propeller is clear and the trigger is locked.
8. Plug in the main connection.
9. Plug in the secondary connection.
10. Test the motor for less then three seconds.
11. Attach the body of the scooter.
12. Remove the nose cone, inspect and clean the o-ring and sealing surfaces.
13. Disconnect the secondary plug for transport.
14. Install the nose cone.

After a couple attempts, this ritual it becomes second nature.  I found it was best to work from the bottom of the scooter up.  If the scooter isn’t on a flat surface, like in the jungle, make sure to flip it over on the nose cone before testing the motor.

We also discussed predive check and break down of the scooters.  I am not going to give you all the procedures, because you will learn them when you take the course with Steve.  About noon, we got the gear loaded in his truck and we headed towards Tulum.  In Tulum, we stopped at Xibalba Dive Shop and picked up another UV-18.  I repeated the prep procedure and loaded the DPV in the truck.

Our first dive was at Cenote Car Wash.  When we arrived the water was tea colored.  I guess with all the rain we have been having, the swamps are unloading tanic water into the Cenote.   The first thing I needed to do was to get my scooter trimmed and weighted properly.  Steve walked me through the process and provided some helpful tips.  He recommended that DPV should be slightly positive with the nose slightly up.  If I was going to spend a lot time below the halocline then I should set it up a little negative at the surface with the same trim.

I was doubtful due to the limited visibility; however as soon as we descended we broke into clear water.  It was like coming out of the clouds.  The tannic ceiling provided a virtual roof and looked exceptionally cool.

We started off by doing figure eights and driving around.  Immediately I noticed how easy it was to manage this scooter.  I had driven a bunch of scooters including UV-18s and always felt awkward and hated it.  I felt like I was fighting the DPVs and I would be exhausted before we finished the dive.  This DPV was different.  It was balanced and I didn’t really have to hold the handle.  I could set the trigger lock and finger it.  I couldn’t believe it.  I had arrived.  It made scootering so much easier.  I just didn’t know it should feel this way, I figured you always had to fight them.

After I got over my euphoria, we moved onto staging drills, lights out touch contact and team communication.  After a couple of hours in the water we headed back to Steve’s place to break down the DPVs and charge them.

The second day we went to Ponderosa.  We made two cave dives.  We practiced installing/removing the primary reel, staging the scooters, team communication, low on air (tank swaps), exit on secondary light, zero visibility touch contact and other skills.  The first dive I wasn’t all that confident and kept stopping to wait for Steve to catch up.  This repeatedly broke rhythm and I blundered the scooter stage procedure.  I had forgotten the hand signals and couldn’t figure out what he was asking me to do.  After a minute or two of watching him do them louder, it came to me and we carried on.  The debriefing was insightful and to the point.  After diving we went back to Steve’s place, broke down the scooters and burn tested mine.  I had 7 minutes of burn time left.

Today, we went to Chac Mool.  Chac Mool is a big power cave with the largest known underwater stalactite.  It is about 90ft tall.  It is a 30 minute (1500ft) swim from the entrance.  I normally use about 42cuft of gas to reach it.  It is about the perfect scooter training dive because it provides an excellent benchmark to test again.  On the scooters pitched at 5 we reached the Monster in 14 minutes.  This included me bumbling with the reel and getting the tow strap entangled around my sidemount tank.

My swimming sac rate, in sidemount gear, is a .7 cuft/min.  I ran some calculations for my swimming dives to the monster and came up with .66.  Tonight, I calculated my sac on the scooter and was surprised to learn that my first dive was a 1.5 and my second was a .97.    Both of those are pretty hideous and leave huge room for improvement.  I think the task loading with the scooter during the installation of the primary reel really afected my sac rate.   I am definitely going to go and make some practice runs with the scooter to try and improve those figures.

A great example of the differences in our sac rates was our gas consumption at Ponderosa.  We scootered the River Run to the change in direction in the line arrows.  It took us just shy of 20 minutes.  In that time I used 450psi out of each tank and Steve used less then 200psi out of each tank.  I was shocked when he handed me his tank and he had used 200psi, I couldn’t believe it.

Besides keeping close track of our trigger time and gas consumption, we towed and towed some more.  Which is good because towing efficiently is harder then it looks.  Being towed is challenging because you have to stay out of the wake, control the scooter between your legs, maintain orientation to the guideline and not annoy your buddy.  Towing is challenging because you are like a semi truck moving through the cave. A semi truck with a failing tail that is apt to hit things if you are not careful.   It is like dragging a plow though the water. This is another skill that could use practice.

At the end of the day we headed back to Steve’s house to break down the scooters and burn test mine.  The burn test went 17 minutes and the Watts Up Meter showed we had 4ah remaining.  This correlated nicely, because the UV-18 has 16ah batteries and I had recorded about 60 minutes of trigger time.  That means we had about ¼ of the battery remaining and the total burn time would have been 77 minutes, which is in the middle of the 45-90 minute range.

Overall the course was a blast.  I really enjoy working with Steve.  He does a lot of this diving and spends a lot time thinking about the procedures.  Luckily, they are born of direct experience and you can feel that as you put them to use.  They just work.

I am glad to be qualified to use scooters now.  They will be an invaluable tool at The Pit.  I already have some other dives in mind.

Tomorrow, I start the stage/multi-stage course.  Since I dive in sidemount, we will do it in sidemount.  Hopefully, on Friday I will have something entertaining to report [Read more →]

After seven months of living in Playa Del Carmen and asking Nando to go cave diving, he finally complied!  Nando had a clear day in his teaching schedule and he could get away from the new baby.  We knew we wanted to go side mounting in some tight passage.  Nando doesn’t pleasure dive in anything but.  We talked about Grand Cenote Down Stream, down stream at Xunaan Ha and the shallow cave at The Pit.  After some negotiation, we decided to go down stream at Car Wash.

Car Wash Cenote is about 7km out Coba Road from Tulum.  It got its name because the taxi drivers used to wash their cars there.  Luckily, they no longer do.  Today, it is a beautiful site with bathrooms, changing rooms and a very nice land manager.  Entrance is $100 Pesos per diver and they close at 5PM.

Car Wash Cenote has two systems connected to it: Car Wash Down Steam and Car Wash Upstream.  Until recently I thought it was one system because you could swim from one to the other.  Well, I was wrong, it is actually two systems.  For the two segments to be considered part of the same system, you must be able to swim between them without being in open water.

The QRSS FAQ on measuring caves lengths states:

“Authentic underwater cave systems must allow a diver to swim to any point in the system without passing through an open water (direct access to the surface) environment. Avoiding an open water portion by swimming underneath a drip line (a rock overhang) to connect two caves is permitted.”

Nando and I had both dove portions of Car Wash Down Stream in the past.  In February, after a dive at Naharon and Car Wash Upstream, my buddy Paul and I did a quick dive in the down stream section.  We hadn’t been there before and hadn’t received any guidance, so we were exploring.  We ended up finding the Chamber of the Ancients section.  That section drops down to 90ft and we did the small circuit in the back. When we returned to the entrance, we discovered earned a deco obligation on our Sunnto computers.  Opps…. Neither of us ever considered we might end up with an obligation.  The lesson is when you do repetitive dives with consistent depth; you really need some awareness and watch your no stop time or plan better.

On this day, Nando and I agreed to make a dive to the Lower White Room first and then if we had enough gas, return the sign, recalculate thirds, and head towards Satin’s Silt Hole.  We reached the end of the line in the Lower White Room in a little under 18 minutes.  A good part of this dive is sidemount only.  The cave goes up into a tight bedding plane full of tanic water.  Then turns left and drops through a restriction and you bust into clear water.  The cave in this section is in excellent condition.  It is highly decorated and stark white.  I guess  its good condition is the result of needing to be in sidemount to reach it.  Unless you go tanks off, you can not reach it in backmount.

On the return we checked out the jump marked by a red arrow just prior to the restriction.  A couple of minutes of hunting and we didn’t find the jump.  I believe it is there, it is on the map, just another opportunity to go searching.

We followed the plan and reached the sign with 1800psi in each tank.  We recalculated and went towards Satin’s Silt Hole.  Looking at the map, I don’t think we entered it.  We swam down the larger passage to the left, tied into the line and found the end, which was another opportunity to jump.

We turned the dive and discovered an unmarked jump.  We had plenty of gas so we elected to check it out.  The line was covered in some super soft floaty silt.  The kind that when you swim by it, it just jumps up at you.  That whole section of the cave is covered in that stuff and it was sidemount cave.  I am sure you can image the result. As the number two man, I got to navigate the cave in limited and zero visibility.  There was at least one restriction that required the removal of a tank.  We turned the dive on thirds as the cave came up to about 10feet.  The exit trip was a little nicer, the silt had settled and I could see where I was going.  It always seems like you have traveled so much further then you really did in the silt out.

Car Wash Down Stream was an excellent sidemount cave dive.  There were tight spaces, restrictions, silt, tanic water, beautiful formations and some inviting no mount leads.  I think it is worth at least one more visit.

When we talk about cave diving, we usually refer to diving upstream or downstream. Upstream and downstream refer to the commonly accepted direction of the flow of the fresh water in the cave system. Here in Mexico, that direction is from inland to the sea traveling perpendicular to the coast. That knowledge is so ingrained locally that the government includes it in its planning documentation. If you take a look at the image (Click it.) of the slide, you will notice red arrows pointing to the coast. The arrows represent the government’s official position on the flow of water around/under Tulum. It is also important to note that there are two versions of the urban planning documents issued by the local government. One issued in 2005 and one in 2007. If you look closely at the 2007 map you will notice the government has included stick maps of the local cave systems. This is a promising sign, the government is starting to incorporate cave survey data.

The problem is there is no empirical evidence to support the current common belief. There is anecdotal evidence that would support those hypothesizes, however it seems it may be incorrect.

On Friday night, Allie and I had the opportunity to go to Akumal and watch a handful of presentations given at the Centro Ecologico Akumal. There were a number of very interesting presentations, including: one on the dry caves of the area, one on the benefits of GIS, the formation of the local caves and one on the movement of water at Car Wash.

The talk about Yucatan cave hydrology and geochemistry was given by Patricia Beddows, a Research Fellow at McMaster University in Hamilton, ON, Canada. Patricia has been traveling to Mexico to study the caves for at least 10 years. Last year she and a team of volunteers performed a dye tracing experiment at Car Wash to determine the flow of the fresh water there. I believe the results are remarkable.

Before I go any further, she has so far performed one dye trace at this particular site Car Wash. Therefore, the results she shared can only be representative of the water flow conditions in the cave at that time. She mentioned that repeat dye tracing may show somewhat different results.

The experiment consisted of deploying two markers. She deployed one dye in the Cell Block section and at Cenote Luke’s Hope (Cenote Zacil Ha). Both sections are upstream or inland. The expected result was that both dyes would be detected at Cenote Carwash. However, what actually happened was quite startling. The dye that was deployed in the Cell Block section, just stayed there. It never really passed the restriction heading downstream towards the coast. So it would seem that at the time of the experiment, the water was not flowing from upstream to downstream as we all believe it does.

The dye that was released at Luke’s Hope also did something remarkable. It moved relatively quickly down to Cenote Carwash, this was expected. It also moved into the Room of Tears section, this was not expected.

It seems that the fresh water is not moving from upstream to downstream at Carwash. The new hypothesis is the water is entering the system from a perpendicular path from the North and then moving down stream and out of the system south. It is also blowing water into the Room of Tears section.

This is import for a couple of reasons. The first is resource planning. If the government assumes the water is moving from inland to the sea in a straight line, they will plan things like dumps and well fields accordingly. However, if the reality is the water is moving unpredictably; then there is a chance those plans will create a public hazard, such as contaminated drinking water.

The second reason it is import is, it means you and I are using the wrong terminology. There was some discussion at dinner about changing from talking about upstream and downstream to inland and coastal sides of the system. We wouldn’t want to be inaccurate when briefing our dives, right! You know how important it is to be accurate in your briefings, don’t you? So get out of the nineties and your halogen lights and into modern times, it will be Costal and Inland from now on.

Lastly, the term upstream gives the impression that the flow will be working with you to assist you in exiting. When in reality, it may be working against you as the finding suggests. For example, when exiting Room of Tears. I bet you never considered that the Room of Tears might be a siphon. A very weak siphon, but a siphon. I can think of at least one place in Nohoch where there is a strong current against you when exiting, where common knowledge would indicate there shouldn’t be water moving against you.

Naturally, you should now ask, “Why isn’t the fresh water moving the direction of the cave?” The answer is equally interesting. In the last million and a half years or so, the sea level has dropped substantially from today’s levels at least 3 times. It was during one of these low periods that the cave system was formed. No one is really sure during which low period the caves formed. Therefore, the caves were formed during a period that had significantly different geomorphic forces at work then are at work today. When the cave was formed, the water did move in the direction of the cave. It was the eroding force that formed the cave.

Today, sea levels are much higher and the caves are full of water. The movement of water beneath the ground on the Yucatan is controlled by: the tides, the macro geologic formations and hydrostatic pressure from inland. (I consider the local caves micro when compared the to entire Yucatan.) The caves we dive are just happy accidents from the ancient past that provide us with hours of enjoyment. It is my unscientific opinion that Patricia’s findings suggest the following, “where the fresh water does flow in the direction of the cave, it is a coincidence”. It is my belief that the Yucatan is too porous and large for the relatively small cave passages to have meaningful effect on the macro movement of the water.

Patricia’s presentation was a call for further research. Every year, as more caves are mapped and more research is completed, we learn more about our favorite dive sites. Sometimes new information turns our commonly accepted knowledge on its ear and forces us to consider that our world is ever more complicated and beautiful then we expect.

On Friday morning our friend Paul flew into town to do some cave diving! It was his first trip after finishing full cave with Protech in November. We planned to do 2 dives a day Friday through Monday. However, the airlines had other plans and his flight was late on Friday, so we were limited to a warm up dive on Friday. First thing we did was to go over to Chac Mool and do a quick gear review. Paul had just gotten a beautiful new Halcyon harness and donut wing. We revised his hose routing a little and tweaked some other minor things. Those minor improvements really made a difference.

The crew was Allie, Paul and myself. Paul and Allie were in backmount and I was in side mount. We got in the water, did our S drill and dropped down. The dive was called immediately on account of Allie not being able to equalize. Unfortunately, she had been suffering a minor cold. There were tears all around and then Paul and I elected to continue the dive. We did a quick S drill and started the dive. Paul did a nice job of running the reel. We made the 30 minute swim down to The Monster. The Monster is the world’s largest underwater stalagetite. It measures 45feet tall and it hangs into a pit that is 90feet deep. It is really stunning the first time you see it. I always want to swim over to it and put my arms around it. We chose to dive Chac Mool becuase it is a realatively easy dive and there is only one T to contend with and that leads to a air doom that is breathable. Most of this dive is pretty ho hum, as you get to The Monster the rooms become more decorated and enjoyable. The return trip was uneventful. When we got back to Playa we decided to go to one of our favorite restaurants, La Cueva Del Chango.

Saturday brought fabulous weather and we headed down to Tulum for some diving. Allie wanted to give her head another day to clear, so Paul and I were on our own. We decided to go to Grand Cenote and do two dives. The first dive was down to the Cuzan Ha Loop. We elected to make this dive a little more complex, so we took the short cut jumping to the left on the first arrow. At the end of the line we jumped back onto the main line and turned left. We gapped at Cenote Ho Tul. The dive was going fantastic. We were making good time and I could tell Paul was in complete sensory overload. When we got to to the jump for the circuit a little miscommunication/confusion occurred. I went to set the spool to close the loop and Paul followed me. When I realized he was behind me, I sent him back and then finished up. We I returned to the main line, we continued the dive. We made it about 3/4 of the way around the circuit and had to turn on thirds. As we exited we cleaned up our gear and took our time. This is a beautiful dive and it is fun. The restriction after Cenote Ho Tul is good fun and I particularly enjoy it.

The second dive was towards Lithium Sunset. Last time I tried to find the jump off the mainline, I just couldn’t figure out where it was. I guess I wasn’t persistent enough. The picture I had in my mind’s eye was short jump, the reality was it is about 50 feet or so. Maybe less if you make it a straight shot. So we made the jump, went to the second arrow and made the short jump to the left. This is another beautiful dive although it is a little less challenging. If there is a no brainer, this is one of them. Just set the cruise control and enjoy the scenery. Some dives are just easier/less engaging then others. Paul was over joyed at the end of the dive. I was super relaxed and really enjoyed the dive. Grand Cenote is really a wonderful place to dive. The cave is bright white almost blue-ish and is highly decorated.

Sunday Allie decided to join us. We planned to go down past Tulum to Cenote Cristal aka Naharon. I wanted to give Paul the experience of the caves north of Tulum, in Tulum and south of Tulum. My experience is that they offer very distinct dives. And let me tell you, Naharon is no slouch! Naharon is feed by swampy lands to the north and west. Therefore the water in the system is tanic and stains everything. Naharon is about the darkest place I have ever dived and Allie and I find it to be a very psychologically challenging. It literally eats HID light. The darkness makes it very tight and unforgiving. This challenge makes the dive some much more rewarding! Once your field of view starts to open up, you discover the the black silk floors and the black stained formations are amazing. It is really like diving into the belly of a beast. On the main line there is a portal in the rock that looks like the jaws of a shark. As I pass through the formation, I imagine being swallowed by the beast. I guess the Halocline room is the belly.

Naharon is a little deeper then most of the other caves we dive. We plan for a depth of about 70feet and to stay out of deco we use 32% EAN. The plan was to head up to the Halocline Room; which is about a 25 minute swim up the main line. The most striking feature of the Halocline Room is the demarcation on the walls between the fresh water and salter water. The wall below the saltwater is perfectly white. The wall above is tanic stained black. My understanding is that the saltwater eats the black stain. It is really stunning and a worthwhile dive. I really want to get down to Naharon with my CCR or a couple of stages. I can only imagine what treasures hide in the inky blackness.

Dive over, it was time for food! We headed into Tulum for some Chicken! I love the chicken in Tulum. Our favorite place to eat is Pollo Bronco. It is an orange building on a corner on the north bound side of the road. Chicken can be had in the following sizes: quarter, half and whole. There are not really any other options. I think you can get pasta instead of rice. But, I never do.

Lunch over, it was time for diving. We drove over to Car Wash for a little dive. Car Wash is a cenote where the taxi drivers used to wash their cars. The land owner has really made some improvements to this site since that time. There are rest rooms, changing rooms and tables to setup on. They have built a reception area at the Luke’s Hope cenote. It is really nice.

This time of year there is a cloudy layer for the first 10 feet in the cenote then visibility opens up. It is really awesome to drop down through the cloud into clear water and to watch a friend do the same. The visibility reminds me of wreck diving in NJ.

This time it was Paul’s job to run the primary. We setup our primary tie in on a tree a couple of feet from another team’s, then we proceeded in. What we found was an unbelievable spider web of line. The team ahead of us had literally criss crossed the cave at different depths at least three times. Paul was confused and I was livid! Message to all you Muppets out there, “CAVE DOESN’T BELONG TO YOU!” There are other teams in the world, have some common decency. We spent an unreasonable amount of time negotiating the other team’s line. In the end we had two choices: call the dive or install our gear woven through theirs. We choose to install our gear. I helped Paul to take the most respectful path possible. Then we hit another snag, Paul’s primary reel was too short. I loaned him a spare Spool and we gapped to the main line. The lesson here is; confirm how much line you have on your primary reel. Don’t take the manufactures word for it. Unfortunately, the cavern debacle cut our penetration short. I think we made it 15 minutes past Luke’s Hope and Paul turned us on thirds.

When we got back to open water, we recalculated thirds and went for a little exploratory dive down stream. Again we ran into the other team. Again they had taken the entire cave to themselves with their handy reel work. What a headache. Please learn to use your reel!

Monday was going to be a short day for Paul and I. Since he hadn’t been to Minotauro, we went over and did the circuit in two dives. I blundered in my briefing, but nothing severe enough to call the dive. I actually realized it as soon as we submerged on the first dive. We setup the circiut and returned. The second dive we completed the circuit. The only thing notable was that I did the in about 1000PSI. I guess all this working out and concentrating on finning technique is paying off.

Paul’s trip was fantastic and we had a great time. Hopefully he will come back soon and we can do some more diving. There are just too many beautiful places to see!