Archive for the ‘Regulators’ Category

Dive Gear Maintenance Made Easy

Wednesday, December 16th, 2015

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Gear Maintenance Made Easy

If you are a serious diver, odds are you’ve invested significant money in your dive gear. So it goes without saying you want to take care of that gear, right? Not only will proper maintenance greatly prolong the life of your gear, but it’s also one of the best insurance policies for staying safe while diving. Regular user maintenance requires that you visually inspect, clean and properly handle all the pieces of your setup using specific steps for both pre- and postdive care. So, before your next dive trip, follow the pre-dive steps in this guide to make sure your gear is safe and ready-to-dive. And at the end of your trip, or once you get home, follow the postdive steps to keep everything in top-notch condition until next time.

Masks, Fins, Snorkels

Predive Stretch out all the straps to look for fine cracks in the rubber; these are especially common in the heavy rubber straps on open-heel fins, and they’re clear signs of impending failure. If you do find any, immediately replace the straps. If you use a “strap wrapper” to cover your rubber mask strap, either slide the cover to the side or remove it so that the strap underneath can be fully inspected. Next, examine the silicone of your mask skirt, the flexible hose of your snorkel and the snorkel’s mouthpiece for any tears. The most common failure area on a mask is the feather-edged seal on the skirt. This can become imperfect or irregular in shape with time and heavy use, and that irregularity can create leaks. Finally, check all the buckles, which can crack, split or become clogged with debris that can interfere with how they function, and check the frame of your mask for cracking, chips or other obvious signs of wear, especially in the areas immediately adjacent to the glass lens.

Postdive To avoid mildew growth, rinse your mask, fins and snorkel in warm, fresh water and allow them to drip dry completely before packing them away. And pack these items loosely so nothing bends the fin blades, crushes the foot pockets or distorts the mask skirt. Leaving these items squashed into a weird position for a long period of time will cause them to take on an unnatural shape.

Regulators/Gauges

Predive It’s a good idea to connect your regulator to a tank when preparing your gear for a dive trip. Take a few breaths from the regulator, a few breaths from the octopus and check the SPG for an accurate reading. Visually inspect all regulator hoses to ensure there are no cracks, make sure there are no holes or tears in the mouthpieces and check the metal fittings for corrosion. If you use hose protectors, slide them away from the first stage to check beneath them. At the same time, look for corrosion on the metal first stage. Cracks in the hoses or obvious corrosion on any of the regulator’s components require professional service from a qualified technician. Next, disconnect the regulator from the tank, replace the dust cover, inhale on each regulator forcefully and hold a vacuum. Each regulator should let in either a very tiny trickle of air or no air at all. Also check each second-stage housing for cracks, and if you have analog, oil-filled gauges, make sure they aren’t leaking any fluid. Most divers now use computers, and although these devices rarely fail, a dead battery can cut a dive day short. So check the battery indicator on your computer and follow the manufacturer’s instructions for when and how to replace these batteries. If you have an analog compass, rotate the housing to ensure that the compass card moves freely.

Postdive When rinsing your regulator, make sure the purge valves on the second stages don’t get depressed and the first stage dust cover is firmly in place. After dunking the entire octopus, rinse your second stages by running warm water through the regulator mouthpiece and out the exhaust diaphragm. Rinse the fitting that connects to your low-pressure inflator by working the slip coupling back and forth while holding it under warm running water.

BCs

Predive Check your BC inflator by connecting it to a regulator that’s hooked to a tank. Shoot a few bursts of air into the BC, then release the inflate button and listen for air leaking into the BC that would indicate a stuck inflator. A technician must repair any leaks before you get in the water. Next, inflate your BC until the pressure-relief valve pops off and let the BC stand for about 20 minutes to see if it holds air pressure. While the BC is inflated, check the cummerbund, waist strap, shoulder straps, tank band and all the buckles for excessive wear. If your BC has metal buckles, check them for corrosion, which will weaken the metal structure and eventually cause the buckle to fail. A buildup of a white chalky substance or green powder in addition to rust are all indications of corrosion. Minor corrosion can generally be cleaned with a stiff brush and a little white vinegar–be sure to rinse the item afterward so the vinegar is thoroughly removed–and a quick spray of food-grade silicone will help prevent future corrosion if routinely applied after your equipment is clean and completely dry.

Postdive Rinse your BC in fresh, warm water. Even better, add a small amount of unscented shampoo or a dive-gear wash solution to the rinse water. Take all the air out of your BC, place it in the bottom of the rinse tank, hold it down with your weights and let it soak for about 30 minutes. Then, drain the tank, rinse the equipment to remove most of the soap, refill the tank with fresh water and allow the equipment to soak a few more minutes to remove any soap residue. To rinse the inside, depress the manual-inflate button and hold the mouthpiece under running water until the BC is 60 to 70 percent full of water. Shake the BC to agitate the water and then drain it through each of the dump valves and the inflator hose. You should use each of the dumps, including the pull dump on the BC inflator hose, to remove salt crystals and sand from each of these important valves. Once you drain the water, fully inflate the BC, allow the remaining water in the BC to settle for a minute or two, and then drain it again. Finally, inflate the BC to about 50 percent of its volume and let it air-dry away from direct sunlight.

Tanks

Predive If you have your own scuba tanks, check the numbers stamped into the metal on the top of each tank, near the valve, for the hydrostatic test date–it expires on the last day of the month five years after the last date of inspection–and check the VIP sticker for the visual inspection date–it expires on the last day of the month one year from the date of inspection. If a tank is out of inspection, it must be inspected again before any dive shop will fill it. Next, check the tank valve for any impact damage or corrosion. Corrosion around the burst disc or the hand wheel can be an early indication that these items will fail. Burst disc failure will cause you to lose all of the air in your cylinder very rapidly, and if the thin brass stem that holds the hand wheel gets too weak, it can break off. Also look at the front of the valve and check the O-rings. If they appear fuzzy or you see obvious nicks or cuts in them, replace them.

Postdive Never store your tanks completely full or completely empty. Without some pressure, empty tanks can take on contaminants and moisture that can lead to corrosion. Full tanks, especially aluminum cylinders, can crack if stored for long periods of time. So, it’s best to store these cylinders with between 300 and 500 psi, and of course, store them where they won’t be knocked over or subjected to any other impacts.

Exposure Suits

Predive Examine wetsuits for tears, cuts or significant fraying around the cuffs, neck and the seams of the suit. Significant areas of missing or “pulled” stitching can lead to split seams, especially in high-stretch suits in which the seams recieve a lot of stress. Make sure the zippers pull smoothly and lubricate them with a thin application of paraffin-based wax where necessary. Drysuits require a more detailed inspection of the cuff and neck seals as well as the dry zipper. Any imperfections, cracks or cuts can cause the seals to leak. Inspect the dry zipper for missing or bent teeth or advanced wear in the fabric that holds the zipper in place. Unlike wetsuits, it is generally cost effective to repair drysuit seals and zippers. Only a qualified service technician should perform these repairs. You must also check the operation of the valves on the suit. Like the low-pressure inflator on a BC, check the drysuit’s inflate valve by attaching it to a tank and operating the valve a few times; it should allow air into the suit easily without sticking or inflating after releasing the button. Checking the suit’s vent valves can be more difficult. Do this by putting the suit on and inflating it completely, wait to see if the suit holds air, then activate each deflate valve several times to make sure they vent properly and reseal as they’re supposed to. If you notice leaks in the suit’s material, patch them according to the manufacturer’s recommendations or return the suit to your dealer for service. Patched leaks may need to cure for 24 hours or more, so it’s best to check your drysuit at least a few days before you plan to use it.

Postdive Exposure suits can be hand washed in a tub of warm water. It is best to use a wetsuit shampoo available from any retail dive facility to help prevent the suit from fading or breaking down the integrity of the rubber. Wetsuits can also be washed in a machine with a hand wash cycle. Take it out before the spin cycle and allow it to drip dry.

Surface Interval For Gear

Always let your equipment dry thoroughly inside and out before packing it away. If you have the room, it is best to hang BCs, exposure suits and regulators in a cool, dry closet. The garage may not be the best place to store your gear, especially if you live in a hot, humid climate. However, many divers lack the space to do this. With the exception of your exposure suit, equipment can be stored in a good-quality piece of dive luggage without damage, but make sure the bag is large enough that the gear doesn’t fold or crimp in unnatural ways. Store your BC about 20 percent full of air to keep the internal sides of the bladder from sticking together. To further protect against age-related damage, apply a light coat of food-grade silicone to all rubber and metal components. Don’t spray the silicone directly on the components. Instead, spray a light coating on a soft cloth and rub it onto your regulator hoses, rubber fin straps and metal buckles. You can also preserve the life of the zippers on your gear bags and exposure suits by applying a dry-suit zipper wax. Simply pull the wax stick along the exterior of the zipper on each side, and then work the zipper back and forth a few times to distribute the wax. Store your mask in a rigid box to protect it from impact. You can add your computer and compass to the box as well. As a final note, before storing your equipment, look for items that need to be replaced or otherwise repaired. It is best to repair these items immediately so that your stored equipment is ready to dive when you are.

Gear Check

Certain components of your equipment require annual inspection and service by a qualified technician. It’s a mistake to assume that if you haven’t used your equipment it doesn’t require service. In fact, most technicians agree that rarely used equipment needs regular service more than equipment that sees more frequent use. Both your regulator and your BC should be checked in accordance with the manufacturer’s recommendations, usually once a year.

ScubaLab: Best Dive Gear of 2015

Wednesday, December 2nd, 2015

This past year ScubaLab tested more than 70 pieces of new gear. Here are the regs, BCs, fins, snorkels and knives that excelled.

GEAR OF THE YEAR: REGS

ScubaLab Regulator Test 2015

See full test results at scubadiving.com/reg-test-2015

With so many regs to test in 2015, we split up our test, evaluating models under $500 (July) and over $500 (August).

How We Test Regulators

ScubaLab put these regs through two tests — the first is conducted on a breathing simulator (objective), and the second by our team of test divers (ergonomic).

Objective Testing

We conducted tests on an ANSTI wet breathing simulator at Dive Lab, a commercial test facility in Panama City Beach, Florida. The simulator measures the effort (work of breathing) required to move air through a regulator as it is subjected, under- water, to a precise series of depths and breathing rates.

The simulator pressurizes the test chamber to simulate depths of 132 fsw, 165 fsw and 198 fsw. Each “breath” by the machine moves 2.5 liters of air through the regulator, at breathing rates of 15, 25 and 30 breaths a minute. These precisely measured volumes of air — 2.5 liters multiplied by the breathing rate — are called Respiratory Minute Volumes (RMVs).

We don’t test on the simulator for a pass/fail grade, but to objectively gauge performance in carefully controlled conditions. You can see how each reg performed on the breathing simulator in the charts that accompany the reviews.

Ergonomic Test Categories

  • Ease of breathing in swimming position

  • Ease of breathing in head-up position

  • Ease of breathing in head-down position

  • Wetness in normal swimming position

  • Wetness in head-down and odd positions

  • Bubble interference in normal swimming position

  • Bubble interference in vertical/stationary position

  • Ease of clearing regulator using the blowing method

  • Ease of clearing regulator using the purge button

  • Purge button stiffness and comfort

  • Comfort of mouthpiece

  • Venturi lever adjustment function and effectiveness

  • Breathing- adjustment-knob function and effectiveness

See the Full Test Results Here


GEAR OF THE YEAR: BCs

SCUBALAB: 13 New BCs Tested

See full test results at scubadiving.com/BC-test

In our June issue we tested 13 new jacket, hybrid and back-inflation BCs for performance, stability and comfort.

How We Test BCs

A ScubaLab BC test has two parts: an in-water ergonomic evaluation by test divers and a series of objective tests we perform in a pool.

Ergonomic Test Categories

  • Assembly

  • Loading Weight System

  • Comfort and Adjustment

  • Attitude and Stability

  • Pockets

  • Valve Operation

  • Ascent Control

  • Surface Floating Position

  • Weight-Ditch System

Objective Tests

  • Flow-Rate Test

  • Buoyant Lift Test

  • Inherent Buoyancy Test

See the Full Test Results Here


GEAR OF THE YEAR: FINS

See full test results at scubadiving.com/fin-test-2015

In our May issue we tested 13 new open-heel and full-foot fins in a wide variety of styles and designs.

How We Test Fins

Fins were also evaluated for weight, buoyancy and the effectiveness of non-slip material on the bottom of the sole.

Fin Test Categories

  • Ease of Donning Fin
  • Adjusting for Fit
  • Fit and Comfort
  • Stability
  • Power vs. Stress
  • Kicking Style
  • Acceleration
  • Maneuverability
  • Surface Swimming
  • Ease of Removing Fin

See the Full Test Results Here


GEAR OF THE YEAR: SNORKELS

ScubaLab Snorkel Test

See full test results at scubadiving.com/snorkels-2015

In our September/October issue we tested a dozen snorkels, including pocket models, for performance, comfort and convenience.

How We Test Snorkels

To evaluate the performance of each snorkel in open-water conditions, the ScubaLab team of test divers snorkeled of the beach at Sebastian Inlet State Park on Florida’s Atlantic Coast in seas of about 2 feet, with an onshore breeze of about 12 knots. Using waterproof test sheets and slates, divers rated each snorkel in seven performance categories, with 1 being poor performance and 5 being excellent. Divers also recorded comments about their experience using each snorkel and ranked their top three favorites in each category.

Ergonomic Test Categories

  • Security, adjustability, convenience and ruggedness of the mask attachment.

  • Comfort, water seal and position of the mouthpiece.

  • Effectiveness in blocking water entry.

  • Effectiveness in removing water by the purge valve or blowing.

  • Ability to supply sufficient air.

  • Operating without excessive noise, such as gurgling or rattling.

  • Weight, dimensions, stability (wobbling) or other factors affecting overall comfort.

See the Full Test Results Here


GEAR OF THE YEAR: KNIVES

See full test results at scubadiving.com/diveknives

In our March/April issue we tested 22 knives for performance, construction and corrosion resistance.

How We Test Knives

We evaluated each knife’s ability to cut several types of line:

  • 1⁄4-inch diamond braid nylon-poly

  • 1⁄4-inch hollow-braid poly

  • 1⁄2-inch braided nylon

  • Heavy (.095-inch) plastic trimmer line.

While we could have used tougher lines (such as Kevlar), we chose the lines we did because they’re the kind of cheap, often-discarded, long-lived materials that we encounter diving.

We made a first cut through a hand-held loop of each type of line, and rated the cutting ability from 1 to 5 (1=Poor and 5=Excellent). Next we cut a double thickness of each line, and then we made 20 repetitive cuts of all lines on a block of soft wood, and followed that with more cuts of hand-held loops (since you’re not likely to find a cutting board when diving). We also scored each knife on the following: the security of its sheath or folding/locking mechanism; the ease of deploying/stowing the knife barehanded and with 5 mm gloves; how it withstood 10 pounds of weight when wedged 1-inch deep in a block of wood; and its overall fit and finish.

See the Full Test Results Here

The Magic of Cave Diving: Five Training Courses You Need to Take

Tuesday, November 3rd, 2015

These Five Courses Will Help You Discover a Deeper Self — Literally

Shining a light into the unknown — there’s nothing that feels more like exploration. But that’s not the only reason divers who enter caves become hooked. It’s a sport where record-breaking discoveries happen every year, and there’s no shortage of boundaries yet to be crossed. But underground glory isn’t the real reason to consider cave train- ing. Even if you never venture much farther than the sun shines, these courses will give you a degree of physical and mental confidence you never thought you could muster.

CAVERN DIVER

“I’ve had students who have recently finished open water training and have just 25 dives under their belt up to advanced trimix open water instructors,” says Johnny Richards of those who enroll in his cavern diver courses.

Dive Rite LX20 Dive Light

Zach Stovall

Gear Essentials: Cave Diving Light

“You’ll need a cave diving light, and you’ll get a lot out of it for other types of diving. Also, ditch the console computer and get a multigas wrist-model computer.” — Karl Shreeves

Contact: diverite.com

All must relearn buoyancy, given that the jump from open water to overhead environments can be jarring.

“Open water is very forgiving,” says Richards. “Vary 3 to 5 feet and it’s no big deal — but in a cave, that can put you on the floor or ceiling.” To help divers cement a new buoyancy foundation, focusing on fine-tuning trim and breathing, Richards instructs in north Florida’s cave systems. These caves better prepare students for one reason: They have flow. On entry, divers power against a current measured in millions of gallons per day. “Flow affects everything — trim, buoyancy, propulsion,” Richards says.

Richards’ favorite classroom is Devil’s Den in Williston, Florida, about 100 miles northwest of Orlando. This cave extends 35,000 feet and flows at 42 million gallons per day.

“Train in complex environments and you’ll easily go anywhere that’s not as challenging,” says Richards. “If you know what Devil’s feels like, you can get a sense of other places.”

Environments like Devil’s Den also help divers shed another nasty habit: the instinct to kick more than necessary.

On the return route, these caves present yet another challenge. “With flow behind you, you have to anticipate buoyancy-control changes before they’re needed,” says Richards. “As I approach the exit at Devil’s Ear, it’s imperative
I make buoyancy changes before that change in depth — otherwise, if I’m neutral, with flow behind me, I’ll have a sudden rapid ascent.”

But even this situation is one that students build up to, starting at Ginnie Springs, 80 miles west of Jacksonville, or an hour north of Devil’s Den. Ginnie, another high-flow cave, is even better suited to beginners thanks to its flow of 35 million gallons per day and a coarse-sand bottom.

“Generally speaking, high-flow cave means low silt potential,” says Richards.

For new cave divers, almost always guilty of kicking too much, this means their zealotry won’t result in a fog of silt and lost visibility for too long. But causing a silt-out is part of the process; divers gain an understanding of what it feels like to have successes and failures. Says Richards, “This isn’t a course where I expect divers to come in and know what they should be doing — it’s a time where a lot of mistakes can happen.”

Go Now: cavediving.com


INTRO TO CAVE DIVING

One of the first things aspiring cave divers must get used to is starting expeditions in the middle of nowhere — often a field or forgotten forest, reachable only by two-track dirt roads. To access Mermaid’s Lair, one of cave diving instructor Cristina Zenato’s favorite classrooms, start by heading to the eastern side of Grand Bahama.

ScubaPro MK25 EVO/G260 Scuba Diving Regulator

Gear Essentials: High-End Regulators

“At this level, you start using an H-valve with two independent regulators. You want robust life support that is dependable, with high performance. You should also look for an oxygen regulator, deco cylinder and backup computer.” — Karl Shreeves

Contact: scubapro.com

“Old Freetown Road is abandoned,” says Zenato. “It used to connect the two sides of the island, and now it’s just a very nice, scenic drive that adds to the adventurous feel.”

Mermaid’s Lair is worth the trek due to how well it suits the needs of beginners. For starters, Zenato rerigged the ropes running through the cave.

“I changed the line, so it’s continuous, with no navigational changes — you can’t take jumps or turns.” Neither of which is allowed in the intro course.

In other words, getting lost would be pretty hard. Nor is depth an issue: Mermaid’s Lair dips to roughly 70 feet, giving divers ample time to practice buoyancy and what Zenato considers the key skill to begin developing at this level: global awareness.

“When you’re cave diving, you can’t think about just one thing,” she says. “You have to be like a little computer, calculating all these things at once, like the line, the light, the cave — and your buddy.”

Part of global awareness is taking in the environment — and that can mean appreciating the scenery.

“In Mermaid’s Lair, the formations change from a rusty orange to a sheen of black to yellowish-white crystals — and then, all of a sudden, everything is covered in black crystals. You don’t expect it to be so different in such a short environment,” says Zenato.

It’s something she’s reminded of nearly every time she shares the cave with someone new. She can hear the “ooh” through the regulator. And afterward, reactions vary wildly.

“Some people talk nonstop, and some are silent, and I can tell their hearts are so full with what they just experienced,” says Zenato. “Either way, I know when they’re hooked.”

Go Now: unexso.com


FULL CAVE DIVER

For Alessandra Figari, graduating a full cave diver is like set- ting a tourist loose in a Venice glass shop. If divers meet her standards for the course, she knows they’re skilled enough to closely approach formations as delicate and unique as hand-blown curios.

Bare Sports X-Mission Drysuit

Zach Stovall

Gear Essentials: Drysuit

“As you go deeper into caves, your dives get longer and a drysuit becomes necessary, especially for the cooler waters found in north Florida cave diving. In warmer waters, such as in Mexico’s Yucatan cave systems, a full 7 mm wetsuit with a hood will usually suffice up to about three hours — beyond that, you might want to wear a drysuit even there.” — Karl Shreeves

Contact: baresports.com

Before she turns them free, she guides them through the blanker slates of Riviera Maya’s underground realm — the caves with fewest decorations. But even those are not without beauty. Chikin Ha is one of her top picks for training full cave divers. Divers first pass through two cenotes lit by thick bands of sunlight. From there, darkness.

“Then it’s two big blocks of rock, and you can’t help but have that feeling of being under the earth,” says Figari. “It’s like being in a Gothic cathedral with all these different pieces of art.”

Inside, trainees work toward following a line in no visibility, handling a lost-diver scenario and sharing air in an overhead environment.

“I make students share air from the deepest point in the cave,” says Figari. “It’s meant to help them work on stress levels.”

When the way in and out is the same, and something happens after 40 minutes in, you have to swim out 40 minutes.

“The only thing that determines whether or not you come out is how you handle yourself,” she says. “The full cave course teaches you how to handle emotion and control the mind in these situations.”

The basics of that control are the same as with any dive course. It comes down to breathing. “If we breathe incorrectly, we cannot control the mind, and that is when we get into big trouble,” she says.

Once they prove themselves, divers are handed the keys to rooms holding even more fascinations, places like the cave Nohoch. Inside, tight passageways are lined with white formations.

“Everything is so small that you feel you should freeze, that just your presence could compromise this environment,” she says. But worry not. “No, of course it won’t. Otherwise, I wouldn’t take anyone there.”

Go Now: cavetrainingmexico.com


DPV CAVE DIVER

Now you’re going places — or, at least, you will be after the diver propulsion vehicle cave course.

Hollis H-160 Diver Propulsion Vehicle

Courtesy Hollis

Gear Essentials: Diver Propulsion Vehicle

“Using a DPV to explore caves is a technical challenge that demands you to be entirely in the moment — you need to be self-disciplined and detailed, and show you can follow the rules and stay within your limits. You should also have lots of prior cave experience — otherwise, you can get yourself into trouble in a hurry.” —Karl Shreeves

Contact: hollis.com

The main motivation for divers to commit to the DPV course might appear to be the intense pleasure of zipping through extended cave systems — a roller-coaster ride past exponentially more formations and decorations than with fins alone.

But there’s a much more practical reason as well: DPVs buy you time.

“You get decent bottom time while keeping reasonable decompression times,” says cave diving instructor Johnny Richards.

This is an understatement. Instead of draining your gas supply on stretches you’ve seen hundreds of times, you zip past the familiar and start your dive with the new.

Exploration 101.

As for the course itself, says Richards, “It’s fairly arduous —lots and lots of skills and drills, such as dead-scooter swims and dead-scooter tows.”

There’s not much on-scooter time during the course, but afterward, it’s free rein. For Richards, use of a DPV opens up places like the Super Room inside Eagle’s Nest, a cave in the town of Weeki Wachee, roughly an hour north of Tampa.
“It’s a big monster of a room with a lot of features and fossils — mostly shells; this was all ocean floor at one time,” says Richards.

In the Little River Spring system, about 90 minutes west of Jacksonville, Richards likes to tar- get the Florida Room before continuing on by fin.

“There’s a point where you must drop the scooter,” says Richards. “The cave becomes like a roller coaster in places — then it becomes tight, with high amounts of silt. From there, you can swim 3,400 feet to the end of the line.”
He’s quick to point out that divers should never actively pursue that marker as a goal.

Says Richards, “It’s something that will naturally occur at some point given time and experience.”

Go Now: cavediving.com


STAGE DIVER

“Cave Diving is all about expanding your comfort zone, step by step,” says Patrick Widmann, an advanced cave diving instructor in the Dominican Republic. The full cave diver course allows finishers to explore a cave using one-third of their tanks; stage cave diver teaches students how to safely add a cylinder to explore even farther.

Hollis SMS 75X Sidemount BC

Zach Stovall

Gear Essentials: Stage Rigging and Sidemount BC

“When you start using stage cylinders, you’ll need more regulators with submersible pressure gauges, and rigging for each. At all levels, sidemount has become a popular option. There’s no reason to be a backmount cave diver if you know you want to dive sidemount — get certified as a PADI tec sidemount diver.” — Karl Shreeves

Contact: hollis.com

Skills taught include team protocols and how to stage and retrieve tanks blind, which simulates a silt-out caused by a tank dropped atop sediment.

This course also aims to strengthen confidence, especially with distance stress — “your mind telling you that you are a long way from home,” Widmann says. “Distance stress never leaves you, even after thousands
of dives. It just becomes a question of when it will set in.”

And it happens farther in after more training dives. For the stage cave diver course, Widmann teaches primarily in two caves. Cueva Taina and El Dudu. Cueva Taina, near the Santo Domingo airport, presents students with a halocline followed by rooms of white walls, stalactites and columns. El Dudu lies near the town of Cabrera, two hours east of Puerto Plata on the northern coast. Past its giant sinkhole opening, the cave’s route, 20 feet deep, winds past unusual water colors, walls stained with tannins and rooms filled with dark-dwelling critters such as bats, scorpions and tarantulas.

When students complete the course, Widmann takes them to Manantial El Toro, a cave outside Punta Cana that is the country’s longest, requiring stages to explore.

Distance stress can be heightened from the start thanks to the cave’s dramatic entry. It’s a 30-minute hike from the car park, then you descend 130 feet by foot. “The entrance is mind-blowing,” says Widmann. “It’s a ginormous dry cave with tree roots hanging from the roof.”

El Toro’s warren unspools to a variety of rooms and terrain, all serving as mental practice for future cave settings. With each new hurdle, divers are tasked with monitoring distance stress.

“There’s a tunnel filled with really rare bacteria that stain the water an opal green,” says Widmann. “It’s studied by NASA scientists.”

Like Alice in Wonderland, divers must be prepared to feel small in a large room, or huge in a small space.

“Going through a room a plane could fly through is much different from a tunnel the size of a computer screen,” says Widmann.

Either way, he reminds divers that it’s not so much about the conditions, but how you handle them.

“If I perceive something as dangerous, my body will react that way with increased breathing rate and risk of accident,” says Widmann. “Rather, we’re training ourselves to perceive our environment as safe so our bodies stay relaxed.”

Go Now: dr-ss.com


What It’s Like To Be A Cave Diver

Cave Diver Jill Heinerth

Courtesy Jill Heinerth

“A privilege,” says filmmaker, photographer and Scuba Diving contributor Jill Heinerth. You can read why caving is so addictive in the November/December “What It’s Like” column from this caver, who is a member of the Explorers Club and Women Divers Hall of Fame, recipient of the Wyland ICON Award for making a difference for our water planet and the Sir Christopher Ondaatje Medal for Exploration from the Royal Canadian Geographical Society, and Scuba Diving‘s Sea Hero of the Year in 2012.

The Best Scuba Regulators Under & Over $500 Tested by SCUBALAB

Wednesday, August 12th, 2015

HOW WE SCORE

ANSTI breathing simulator results shown here are based on a score of 1 to 5, where 5 represents excellent performance with work-of-breathing measurements of 1 joule per liter or less at carefully regulated depths and breathing rates and volumes.

HOW WE TEST

ScubaLab put these regs through two tests — the first is conducted on a breathing simulator, and the second by our team of test divers.

OBJECTIVE TESTING

We conducted tests on an ANSTI wet breathing simulator at Dive Lab, a commercial test facility in Panama City Beach, Florida. The simulator measures the effort (work of breathing) required to move air through a regulator as it is subjected, under- water, to a precise series of depths and breathing rates.

The simulator pressurizes the test chamber to simulate depths of 132 fsw,165 fsw and 198 fsw. Each “breath” by the machine moves 2.5 liters of air through the regulator, at breath- ing rates of 15, 25 and 30 breaths a minute. These precisely measured volumes of air — 2.5 liters multi- plied by the breathing rate — are called Respiratory Minute Volumes (RMVs).

37.5 RMV @ 132 fsw:
This represents the maximum recreational depth at a somewhat aggressive breathing rate.

75 RMV @ 132 fsw:
This simulates the potential demand at maximum recreational depth for a diver at an extremely heavy work rate, or loosely simulates two divers buddy breathing at a somewhat aggressive rate.

62.5 RMV @ 165 fsw:
This represents the European conformance standard EN250, and is also the depth and breathing rate commonly used by manufacturers when determining a regulator’s performance.

62.5 RMV @ 198 fsw:
This is the U.S. Navy’s Class A test depth and breathing rate (although the Navy uses a higher HP supply pressure than we do). The simulator monitors how much effort is required to breathe, measuring the work of breathing in joules per liter (j/l). In our ratings, a score of 1=3j/l or greater; 2 = 2.26-3.0 j/l; 3 = 1.51-2.25 j/l; 4 = 1.1-1.50 j/l; and 5=1j/l or less.

We don’t test on the simulator for a pass/fail grade, but to objectively gauge performance in carefully controlled conditions. You can see how each reg performed on the breathing simulator in the charts that accompany the reviews.

ERGONOMIC TESTING

We conducted these tests at Alexander Springs in Florida with a team of divers who recorded their scores during their dives using underwater slates and waterproof test sheets. Divers evaluated each regulator in 13 specific performance areas, assigning scores from 5 (excellent) to1 (poor), and recording their observations and comments about factors that determine the comfort and performance of the reg while they were actually being used.

ERGO TEST CATEGORIES

1 Ease of breathing in swimming position
2 Ease of breathing in head-up position
3 Ease of breathing in head-down position
4 Wetness in normal swimming position
5 Wetness in head-down and odd positions
6 Bubble interference in normal swimming position
7 Bubble interference in vertical/stationary position
8 Ease of clearing regulator using the blowing method
9 Ease of clearing regulator using the purge button
10 Purge button stiffness and comfort
11 Comfort of mouthpiece
12 Venturi lever adjustment function and effectiveness
13 Breathing- adjustment-knob function and effectiveness


WHAT YOU GET FOR UNDER $500

Regs in this price range tend to be short on frills. None we tested in this price category had breathing resistance adjustments, rotating first stages, swivel hose connections, titanium goodies, etc. In some cases, that means you’re giving up a bit of comfort or convenience, such as the additional options for hose routing that you get with a rotating first stage, or the ability to precisely fine-tune your reg’s breathing resistance at a particular depth and workload. But that’s not to say these regs cut corners when it comes to performance — in our testing some showed work-of- breathing scores on the ANSTI machine and comfort and ease of breathing in the ergo tests to rival regs with much heftier price tags. Of course, their lack of breathing resistance adjustments means it’s especially important that their factory presets strike the right compromise between too much and too little at varying depths and breathing rates. Our testing suggests they usually hit very close to the mark.

WHAT YOU GET FOR OVER $500

The regs we tested in this price range showed slightly higher performance overall on the breathing simulator than their thriftier brethren (principally at greater depths and extreme breathing rates). But testers found that some features on these regs added comfort and convenience. Breathing adjustments allowed fine-tuning airflow with changes in depth or breathing demands. Exotic materials helped keep components light for comfort without sacrificing performance or durability. And first-stage features like rotating barrels or extra ports provided more hose-routing options.

Q: What makes a reg a favorite?

A: As you’d expect for a piece of gear as personal as a reg, test divers have varying opinions. But the regs our testers liked best had controls that were easy to use and effective (and well marked). They had second stages that were compact and didn’t create bubble interference. They had purge controls that could clear the reg effectively without an excessive blast of air. And — above all else — they delivered smooth, quiet breathing, with as little effort as possible.
Roger Roy, ScubaLab Director

REG CLEANING

Don’t just give your reg a quick rinse after diving — give it a good long soak, especially if you’ve done multiple dives in salt water. Always be sure to give clean, fresh water time to wash away any salt that has accumulated before it can cause corrosion or other damage to sensitive parts such as valves and diaphragms. If possible, soak your reg while it’s installed on a tank and pressurized, which will prevent water from getting inside. If it’s not pressurized, don’t press the purge while it’s soaking because that could let water inside.

PERFORMANCE YOU CAN SEE

The graphs below show results of ANSTI testing on the same reg at different depths and breathing rates. The loops go clockwise, starting at the right, as inhalation begins, and moving to the left, where exhalation starts. Below the centerline shows the negative pressure required to inhale; above shows the positive pressure needed to exhale, measured in millibars.

ANSTI Breathing Rates for SCUBALAB

Photo Illustration by Scubadiving.com

ANSTI Breathing Rates for SCUBALAB

The top graph was taken at 132 feet at 15 breaths per minute, and recorded a work-of-breathing score of .73 joules per liter — excellent performance, showing it was able to deliver air at that rate and depth with little effort. The next graph shows the same reg at 181 feet and a breathing rate of 30 breaths per minute. The denser air, higher water pressure and rapid breathing are taxing the reg, pushing its work- of-breathing score to 1.76 joules per liter — good, but a difference a diver would feel.