Recharging Desiccant

I'm just hours away from my next trip... departing to Cozumel, Mexico for a stay of a little over two months! Camera is ready, dive gear (including a whole lotta cave gear) is packed, everything looks good to go. BUT. While packing my desiccant I noticed I hadn't dried it in a while. Probably not since last year's Cozumel trip. Here's some notes on when you should dry your desiccant and how to do it.

I use SeaLife "Moisture Munchers" which come 10 to a pack for about $8. SeaLife part number SL911. The main reason I use these is because they are rechargeable, and have a built-in dye indicator to show their condition. They are bright blue when fully dry, and eventually fade to a dull pink when they are used up. Typically if they are starting to look between purple and pink is when I stop using a Moisture Muncher capsule.

The picture above shows three capsules successfully recharged, and three that blew up probably because their holes were too small to let the rapidly expanding moisture escape. Note the deep rich cobalt blue colour. This is your goal!

To recharge, follow these directions:

• Set oven temperature to 275 F (135 C)
  
• Place used capsules between two pieces of corrugated cardboard, and put the carboard on a baking sheet
  
• Place baking sheet in the middle rack of the oven
  
• Bake for 20-40 minutes, checking every 10 minutes or so for that cobalt blue colour which indicates they are finished
  
• Bake additional 10-15 minutes, to be sure the desiccant in the middle of each capsule is done
  

Important!

• Do not use a toaster oven. They are very bad at regulating temperature and you will either melt the capsules or cause the cardboard to catch on fire!
  
• Do not leave in oven longer than 1 hour
  
• You may need to poke larger holes in some of the capsules especially if they are wet
  
• The reason you use cardboard is to protect capsules from radiative heat and to avoid contact with the metal baking pan. You only want convective heat to remove the moisture. Radiative heat will melt and deform the capsules!
  

In some cases, if the capsules are saturated or you use too high a heat, they will blow up like balloons. If this happens you can still use the capsule (as long as the desiccant isn't leaking out of them) but they may not fit inside your underwater housing anymore. I just throw 'em out if they get deformed. They're pretty cheap and I buy several packets at a time.

Remember! Desiccant is a drying agent, not a sponge. It will absorb small quantities of moisture in ambient air trapped in your housing. It will NOT protect your camera if visible moisture gets in there (such as flooding).

I don't know if there is a limit to how many times you can recharge your desiccant capsules. Probably as long as they recharge to a blue colour they are still usable. I have recharged mine at least 5 cycles now.

Ready for Cozumel (Almost)

Yes! Take a look at this beauty. Looks like a monster, no? It is my new Aquatica Pro Digital housing for the Canon 5D Mark II. Top-of-the-line equipment. And I've fully tricked it out for both still and video use!

I received the housing about 2 weeks ago, just in time to fabricate a slew of parts to retrofit the video lights. The lights themselves were borrowed off my Stingray II video housing, since they still work extremely well. I fabricated a mounting plate for the light arms, and a battery tray for the battery pods. This has taken me about 10 days to do, an hour or two per day. Lots of measuring and adjusting for this custom job.

I also made a carry handle (in blue) to make it easier for deckhands to grab the housing safely when I pass it up at the end of a dive. However, after weighing the whole rig and learning it was about 29 lbs fully loaded, I am thinking that it will need to be moved from water to boat in more than one step. It will weigh closer to 40 lbs if I ever decide to outfit two Ikelite 400's instead of one. Very likely, I'll choose only one mode of shooting for a dive (video or still) and leave the unnecessary hardware at home.

Working with this housing has presented a few new challenges:

There is no eTTL coverter available for the Canon 5D Mark II. I had hoped to use my old Heinrichs-Weikamp eTTL converter but all my tests showed it just doesn't understand what the Canon 5D/II is trying to tell it. The strobes simply don't fire. The Aquatica 5D/II housing has the strobes wired straight, without any converter. This is good enough for manual shooting so I'll have to adapt.

Nobody makes an external color compensation filter for a 5" port. So I'll be doing a lot more manual white balancing. I'm not sure how well this will work for video, however.

Since the Canon 5D/II will not autofocus while shooting video, it would have been great to have a manual focus ring for my lenses. Unfortunately, the focus knob in the flat port is too far away from the focus ring of the lens. Any gear would interfere with the lens rim. This is something I hope to work on when I get back from Coz.

So... what's next? 70 glorious days in Cozumel Mexico where I get to learn how to take stunning 21 megapixel photos with this rig. Add video to that and I'll be very, very busy!

Oops...

Just after the photo shoot, I broke the light arm mounting plate by grabbing one of the arms and pulling upwards. I had made the plate out of plexiglas and apparently the stuff is too brittle for what I'm trying to do. Good thing I learned this now! I still have plenty of time to fabricate a new one out of polycarb, which should be significantly stronger.

What I Dive With and Why

I now have 9 years of scuba diving under my belt, still young by the standards of many in the industry who've been diving all their lives. Neither of my parents have any clue why I do cave diving. Come to think of it, neither do any of my friends.

I thought I'd share a brief list of the equipment that goes with me cave diving, while mentioning good (and bad) things about the specific brands and mods I've chosen.

Wetsuits

Caves in Mexico are typically 75-77 degrees F. I layer two wetsuits: a 3 mil full length Henderson and a 3 mil shorty Mares. The Mares has been with me my entire 9 years of scuba diving and it's still in incredibly good shape. Henderson is crap/cheap dive gear, this is my 3rd piece and probably my last. They just don't keep up their thermal properties after 100 dives. My plan now is to get one of the new WaterProof W1 front-zip 5 mil wetsuits, as soon as they come out next year.

Regulators

All 3 of my regulator sets (2 x DIN for doubles, and 1 x Yoke for stage tank and open water) are Atomic Aquatics B1/B2 sets. All were purchased off eBay for really good prices. I've had minimal problems with any of them. Performance is as good as everyone says. I highly recommend Atomic Aquatics.

On 2 of the 3 second stage regulators I have a SeaCure mouthpiece. This is made of a special plastic that is made moldable when exposed to very hot water. In this way you can customize it for your mouth the same way that wrestlers' mouthpieces are molded. It adds a LOT of comfort to the regulator, and I find my jaw almost totally relaxed when diving with it. This is extremely important in cave diving, when you want to be 2 or more hours at a time breathing off your regs.

Lights

My primaries are a Dive Rite H10 10 Watt HID and a Dive Rite 500 Lumen LED. I now wear both when cave diving so I have a primary primary and an alternate primary, in addition to my two backups. The H10 has been good to me but lacks the power I desire for cave dive videography.

During all last week I was using Sandra's 21 Watt Sartek, usually instead of my H10. But sometimes I carried both the corded HIDs. The Sartek was sometimes difficult to get lit, either the battery connection would be loose or there would be a problem with the switch. But once running it was a fine piece of equipment. Until the 3-year old batteries died. The light would suddenly start to flicker, go blue and purple, then dim quickly. From flicker to dead was only about 45 seconds. Not much warning! I always had an alternate primary so it was not much hassle. It died on me in Labna Ha, Dos Ojos, and Pet Cemetery. I never once had to resort to my backups.

I'd like to upgrade to a 35W or 50W model HID (probably not Dive Rite) but LED technology is catching up fast. That makes purchasing decisions on a new light rather difficult. If Salvo were still in business I'd be buying their 35 Watt HID light about now. As things are, I don't know what light I'll be diving with a year from now.

Fins

The two most popular models of fins among cave divers are Jet Fins and Mares Quattros. Sure, there are others used but these are the two I see most often. I am a dedicated fan of Mares Quattros both for cave and open water. My fins are configured with spring heel straps. I recommend spring straps for ANY fins used for ANY kind of scuba diving.

BCD/Wing

Dive Rite Transpac II with Rec Wings (51 lbs lift). I like this combo because it easily configures for both single and double tanks so I only have to carry one BCD for both cave and open water.

Computers

My primary computer is now the Suunto HelO2, so I can change gas mixes during a dive. Definitely important when staging bottles of Nitrox in cave diving! The HelO2 has a radio transmitter so I have one less hose to tangle me for open water. For cave diving I use a regular SPG (standard pressure gauge) in addition to the radio transmitter, for redundancy. I find myself almost never looking at the SPG. The exception was when I used Sandra's 35 Watt Salvo. I think the high-frequency ballast in that particular light interfered with the receiver. The only way I could get tank pressure on the HelO2 was to hold my right arm behind my back, away from the light head in my left hand. During that dive it was inconvenient to hold my hand back there the entire dive so I just used the SPG instead.

My backup computer is a Suunto Vyper which has also been with me for all nine years of my diving. It became my primary computer for only one dive this week, at Tux Kubaxa, because I accidentally left the HelO2 back in my hotel room that morning.

The HelO2, the Cobra it replaced, and my Vyper all have a user-replaceable CR2450 lithium battery. Replacing the battery myself instead of sending the computer in for service has saved me $tons$ of money. Sometimes, though, CR2450 batteries are hard to find in resort locations.

Picture from The Chapel

(c)2009 Sandra Haars. All Rights Reserved.

The picture is of me floating on my back in the The Chapel Room of Ponderosa, as we'd surfaced for a 20-minute break. I really enjoyed drifting slowly, watching stalactites slip by like inverted skyscrapers. Sandra Haars gave me permission to post this picture on my blog; it is one of very few that I have of myself cave diving.

Nohoch Nah Chich

And so... so... suddenly it seems! The last full day and last dives of the trip. Connie always seems to do Nohoch on the last day of her cave dive weeks. As I've mentioned before on this blog, I've probably done cave diving at Nohoch more than any other cave except for Aerolito on Cozumel. So I don't have a lot new to say.

For the first (very long) dive, I went in the large group of six divers led by Connie up Charlie's and Parker's lines. Up past the small cenote back on the main line where you can still find the coffee cups left as markers by the original explorers. The dive was turned at the cenote (on end-of-plan) and back down the main line, with a quick stop at the NatGeo platform. Then nine minutes back to Nohoch main entrance. The dive time was a short 89 minutes.

Jim and I wanted to go back in and do a different line as a team of two, with possible adventuring on side passages as we came across them. As only one other team of two were going for a (different) 2nd dive, and that we were going to use the same tanks it was to be a shorter dive... but of course I wanted to make the most of it! (Hey... it was going to be my last cave dive for a few months and this was the first opportunity for just Jim and I to go on our own. The others who didn't dive could just get eaten by skeeters while I enjoyed the cave!)

First things first, Sandra's 21 Watt Sartek was assuredly at the end of its battery life. It had been typically quitting on me after about 100 minutes so I needed to change out. My 10 watt corded light was in the van which would have meant 10-15 minutes delay to get it, but Sandra generously offered me use of her Super Power 35 Watt Salvo HID. Oh! What a light! I'd been coveting it since I first dove with Sandra two years ago. So, a quick switch on primaries while still in the water and off we went!

Our plan was to do the smaller passage line that led downstream from the cenote, with me as lead diver. Starting gas was a bit over 2,000 psi. This is the same line that I discovered with Glenn several years ago by accident. We had a great time! I passed about three jumps, including the reach-gap I recognized as the one that led to a very shallow and moderate flow downstream. Flow like that we really didn't want to get caught in -- I'd warned Jim about watching for the reach gap and I referenced it when we passed.

We passed about two more jumps that went right, then arbitrarily I chose the 4th jump to the right as a change in our route. Jim agreed and soon Sandra's 35W sunbeam was showing me new passage I'd never seen before. We went thru a stalactite/stalagmite restriction, then came across one of the weirdest speleothem formations I'd ever seen. It looked like honeycomb lattice into which delicate stalactites had grown and woven their way through. Then the bottom of the lattice washed away so the whole wall of the stuff was suspended from the ceiling. Awesome!!! Yet another place I have to bring a camera next time.

We took several more side jumps in rapid succession, ending 20 or 50 feet from the previous jump. Twice I am sure we hit the main line and then I realised we were in the same maze of jumps that Bill and I visited last January. We exhausted these as reels allowed, having lots of fun, for another 15 minutes or so then called the dive on time. We both still had lots of air time. We hit the main line one last time, on a long jump very close to the NatGeo platform. This is where we officially called the dive on end-of-plan. I think this jump had been cut back several feet from where it used to be. It wasn't a reach gap before, but now it is difficult to spot from the main line. I wonder why they cut it back so far...? And who is "they" anyway?

On the way out we passed a group of snorkelers touring the cavern zone with flashlights. They seemed obnoxiously excited to see cave divers in full gear. (Note: snorkelers are not permitted to have fins in Nohoch, I guess so they can't get themselves in any real trouble in the cave.) I honored their shining lights in my eyes by patently ignoring them as we passed. We returned to the cenote after 61 minutes, maximum depth of 21 feet and a temperature of 77 degrees F.

Tux Kubaxa and Minotauro

Originally Connie planned for us to go to Tux Kubaxa for two dives, the most remote cenote of all the sites she normally visits during her cave weeks. Tux Kubaxa is what she calls a Power Cave which I think means a cave with very large and highly decorated passageways. Two dives would mean we spend the day in heavily mosquito infested jungle, but we'd only have to do one long van ride. A ride so punishing that I now pad my seat with my two wetsuits and a towel to reduce the jarring impact on my glutenus maximus when we visit this cave.

A poll taken the night before showed most divers would rather do two different caves instead of two dives at Tux Kubaxa. I was in favour of two different systems, mostly because I'd done Tux Kubaxa several times before and didn't see getting two dives with enough variation to keep it interesting. However I loved Jim's answer to her poll most: "I just wanna dive." Connie suggested Minotauro for the afternoon dive which was immediately met with enthusiastic approval.

On to the cave dive report!

Tux Kubaxa

Mosquitoes were particularly bad at this site, as I expected. In anticipation of this, I had taken off my T-shirt back in the hotel room and sprayed the back of it with Ben's 100 DEET, as well as hitting my legs and arms thoroughly with the stuff. Compulsive application paid off for me, but everyone else on the tour were madly swatting skeeters as soon as they got out of the van.

One of the feature attractions of Tux Kubaxa are piles of prehistoric animal bones, in varying states of completeness and condition. I'd seen the mastodon bones every other trip so I was hoping to do something different. Fortunately, my dive partner Sandra was up for splitting off from the main group, and I wanted to see the sloth bones found in another passage. We made a team of 2 and were last into the cave system. Sandra ran reels because she'd been there before. So... Left at the "T" intersection, then two righthand jumps just past the first cenote we encountered (beautiful azure light streaming through a large breakdown area) and a mere 200 feet later through surprisingly small (for Tux Kubaxa) and HIGHLY decorated passageway and there was the pile of sloth bones! They seemed rather big for a sloth, at least judging by the vertebrae. Or maybe it's that "Objects appear closer in water than they actually are" phenomenon. I tried to see a jawbone or skull but it looked like those could have been removed. All the ribs, vertebrae and other bits seemed to be there though. I hear rumors that cave divers are becoming more brazen about taking "trophies" from caves for their personal museums and mantles. What was funny about the sloth bone site is that I did not see any of the Mexican INAH preservation/identifier cones.

The passageway was so entrancingly beautiful! After gawking at the bones for several minutes I checked my time (52 minutes) and air (300 psi above turn point) and showed Sandra my gauge, with a question as to whether we could continue down the line. She indicated she was cold (her semi-drysuit had been leaking progressively worse as the week went on) so we turned the dive and were out of the cave again at exactly 100 minutes. I *loved* the tour and these new passageways are another place I will have to take my camera with a wide-angle lens. And lots of strobe power.

Minotauro

This cave is often on Connie's tour weeks because it has a little bit of everything: halocline, restrictions, speleothems, breakdown rooms, solution cave,... everything except big rooms. The first 10 minutes of passageway you traverse from the cenote are a nightmare for anyone who doesn't have their buoyancy down to experienced cave diver standards. Or any cave diver who might get claustrophobic. If it's not narrow vertically, then it bends or squeezes horizontally.

Minotauro's main line is a circuit, ending back on itself pretty much where that narrow entrance passage ends. Connie likes to close the gap to complete the circuit, then proceed on the main line counter-clockwise. There are many side passages that radiate outwards from the circle made by the main line. Connie's team of 5 divers went ahead of ours but took a different jump to cenote Escalera which was before our jump to cenote Estrella. Because of this, our team entered the deeper part of the cave with the halocline first. As 3rd diver on the team I didn't get the best view of the halocline, but in some of the wider sections I was able to move a bit left or right of the other divers' wake and get the full effect. As a test, I pulled out my Dive Rite LED 500 lumen alternate primary to see the difference of colour temperature between LED and HID. (I had Sandra's 21 Watt Sartek HID for this dive.) Hands down, the HID pierces both fresh and salt water better, and the HID renders prettier (truer?) colours in the salt water layer. LED's still have a way to go before I will want to replace my HID primary.

About 200-300 feet before one reaches cenote Estrella, there is a bedding plane restriction that is a mere 18-20 inches tall and maybe 30 feet long. It is not difficult for an average sized diver in back-mounted doubles to negotiate. But it does take patience, proper trim, good technique and shallow breaths! It's probably a good place for a valve roll-off too, if you're not paying attention to your tanks. On my way to Estrella I tried to do a clever sideways traverse thru the bedding plane. That sort of worked but it wasn't smooth. On my way back, I paid much more attention to where the plane seemed thickest. I was lining myself up both mentally and physically, by stretching my arms out in front of me and dropping my heels. Then I start hearing someone singing the Mighty Mouse theme! It was Jim, right behind me commenting on my simulated-Superman pose.

Anyway, the way back was easier, and it wasn't long before we were back on the main line looking at the white mouse, the black mouse and the plastic skeleton that one of Connie's group members from years ago left on a stalagmite. (If you don't know what I'm talking about, don't worry about it.)

Total time in Minotauro: 84 minutes not including the minutes spent relaxing in cenonte Estrella. Water temperature: 77 degrees F.

Kicked Off the Team

I am rarely pushed to such measures, but where safety is concerned such actions are necessary. One of the divers with us this week is what I'd call "below par." Not in terms of equipment or fitness or even training... but in technique and safety awareness. I was not the only one with this feeling, but I was "voted" to be the Bad Cop: the one to talk to Connie about it.

And so it was. Connie traded the team members a bit for our two dives today and it made a difference in terms of our comfort and enjoyment. Sorry if I seem an ass, but when safety is in question I don't cut corners... or take unwarranted risks. If those unwarranted risks come in the form of a diver who doesn't know what he/she is doing, then I'm not diving with them. Simple as that.