The word SCUBA is an acronym for Self Contained Underwater Breathing Apparatus. Scuba equipment is life support equipment. It's easy for divers to forget this. And it is easy for equipment manufacturers and retailers to forget or "overlook" this. When purchasing dive equipment you should not weigh the co$t of a piece of equipment against its quality and functionality. There are many useless colorful gimmicks being sold that do nothing to benefit a divers safety and overall pleasure of diving. It is common to see that the higher the price tag, the less practical a product becomes. But thats not always the case.

Dive equipment is often sold with a 100% mark-up. If a retailer sells you a $100.00 pair of fins that are completely adequate for the diving you do, they should make $50.00 in profit. And that's fair. If they sell you a $200.00 pair of colorful gimmicky fins that don't work properly, they will probably make a $100.00 profit and put your safety at risk. That's not fair ! But you can see were the motivation to sell gimmicky dive gear might come from. Whatever you pay, you need equipment that will supply you with maximum functionality and the ability to optimize safety while in the water.

We all want to keep our dive shops doors open. But "NOT" if it means ripping off a diver by selling them inadequate life support equipment. Do your homework and talk to people who are diving extensively and regularly. Magazine articles are not always good resources. Writers and publishers are paid to advertise for many companies and generally take a none bias position in order to keep these advertisers purchasing space in their magazines.

Equipment failure points are often overlooked by consumers of dive equipment. Take for example a Buoyancy Compensation Device (BCD) that has multiple gizmo's like multiple exhaust dump valves and fancy inflator hoses protruding through the inflatable bladder, ect. ect.. The more voids that go through this bladder the higher the likelihood of having a severe leak. This could make the flotation of this device either inadequate or completely unavailable. Another example is dive fins that come with fancy plastic strap buckles. These things are supposably designed to make in easier for the consumer to remove the fin from their feet. The problem is that plastic is delicate and cracks. If a fin strap buckle were to break far from the beach, boat or even worse, a cave entrance / exit point, the diver might find themselves in trouble. Here is an article written by a long time dive shop owner and friend of mine, Jim Hoffman. He gives in-depth examples of how divers are getting screwed when purchasing "Dive Gear".

Lets look at some of the basic dive equipment. For "SCUBA" dives, I prefer the XL Scuba Pro Jetfins. The high quality rubber that these fins are made with provide the proper amount of flex. Vents help get the diver moving in the right direction. The heavier weight of these rubber fins complements a divers fulcrum point buy adding negative ballast to their feet. This is needed because "Scuba" equipment is very top heavy, with brass tank valves and first stage regulators located near the neck of a divers body. This weight tends to cause a diver to want to roll over head first. Divers who are top heavy tend to compensate by diving with their feet below the plain of their bodies. This poor trim creates drag, buoyancy control issues, increase in gas usage and is an overall insufficient way to swim.

Split fins are some of the most ridiculous gimmicks I have seen hit our sport. People who sell these things will tell you, "they are easier to kick". No kidding ! If a fin doesn't push water, it will be easier to kick. Duh! Try fighting a current when the fin doesn't push water. Divers who buy these fins will tell you the same thing. But they are simply justifying the purchase of these highly priced gimmicks. Suckers ! A skilled diver incorporates a variety of finning techniques and variations of each of them. Flutter kicks, modified flutters, frog kick, modified frog kicks, shuffle kicks, helicopter turn, backwards scowling ect, ect. Split fins will not work with many of these techniques.

Fin "spring straps" can be added to replace rubber straps when diving with a drysuit. These compensate for the ballooning effect as gas shifts to and from the feet of the drysuit. Stainless steel spring straps don't break from ozone related deterioration. It's funny when I think back to the early 1980's when Oceanic's Farallon Fins first used spring straps. They seemed a little over the top and very few divers actually used them. Today, a large percentage of the technical dive community and many recreational divers have adapted spring straps to their fins. Many equipment manufacturers have capitalized by making their own variations of these devices. And a few have even screwed that up. Understanding what you are looking for is key to buying a good product and staying clear of the gimmicks. Keep it simple and think it out before making a purchase.
Scuba Pro dive finsOceanic spring strap
"Skin Divers" also known as "Breathe Hold Divers" require a completely different style of fin. Skin divers are more streamlined than a scuba diver. The are not pushing around heavy, bulky scuba equipment. A more flexible long bladed fin works well. Heavy fins are not desired since there is no heavy scuba equipment to compensate for. Skin Diving fins often come with a full boot pocket and don't require a hard soled bootie to be worn inside. Unlike stiffer scuba fins which are required to provide more torque, these fins are designed to allow a streamlined skin diver to swim fast with minimal effort. Some skin diving fins are made of lighter fiber composite materials, such Carbon Fiber.
gimmick finsJohn's dive masks
Dive masks are another basic equipment item. They come in a variety of shapes, sizes and colors. Comfort and fit are key points when looking for a good dive mask. I prefer to keep it simple, so I often choose a low profile mask. No purge valve, no side windows or fancy quick release buckles. Ah, no gimmicks ! A black silicon skirts help keep light from reflecting on the inside of the glass. Silicon doesn't rot from ozone and creates a great water tight seal. Silicon also causes less allergenic reactions to skin than neoprene and rubber. Tempered glass is of absolute importance in preventing shattered glass from damaging your eyes.

In technical diving, a team member might choose to carry a backup mask. This is generally carried in a pocket attached to their exposure suit. A smaller framed masks will fit nicely. There are also "Frame-less" masks in which the silicon skirt holds the lenses in place. When purchasing a new mask, use a light abrasive such as toothpaste to scrub the silicon preservative out of the inside of the mask. This will help minimize fogging.

Mask straps are often exchanged for a soft neoprene backed nylon strap. These straps are not as easily broken and are quick to adjust to any sized head. If needed, a snorkel can be quickly installed. I don't see color correction or tinted lenses necessary. I believe these sort of things are just another gimmick designed to make the manufacturer and retailer more money, without offering the diver any real benefits.
neoprene mask strap
Snorkels are tools used in breath hold diving (skin diving) and allow the diver to keep his or her face in the water while swimming on the surface. They do not provide a breathing source while underwater. Oh, laugh now! But I have met several people who didn't realize this. Some recreational divers feel that snorkels are life support equipment. This is in the sense that snorkels allow a diver to breath if floating on the surface with heavy surface chop. Personally, I think this is nonsense. A diver floating upright on the surface will have a hard time keeping water out of a snorkel, particularly since the snorkel will now be angled back and not much higher out of the water than their mouth. If the dive gear were weighing them down then they need to get out of it.
IMG_0567
Scuba Diving with a snorkel attached to the mask creates an entanglement hazard. Either with plants such as kelp, ropes, fishing line or even scuba hoses. Scuba divers should have plenty of reserved air left in their tanks to breath on the surface for a while. Otherwise, get out of the gear. Drop the lead, inflate the BCD and lay on top of it. When weighing the advantages of having a snorkel against the disadvantages of having a snorkel on a scuba dive, many will realize that they actually become a liability when worn on the mask. If necessary, a snorkel can be put inside of a pocket.

Thermal protection is extremely important in having a comfortable and safe dive. Temperature has effects on the human body which can elevate stress and predispose you to physiological injuries, like hypothermia to decompression illness.
Understanding how a dive suits work is critical in making the proper choice when purchasing one.
wet suit, dry suit
Water is a dense medium that has the capability to wick temperature away from the body. No matter what type of exposure suit a diver wears, if the suit is not capable of maintaining 98 degrees fahrenheit , the bodies temperature will drop as time passes. Any lower than about 95 degrees, serious hypothermia is inevitable. On the other hand, a dive suit can also create too much warmth and hyperthermia is possible.

Over the past 30 years, I have owned many different diving suits. Wetsuits provide reasonable protection for shorter dives in waters warmer than 60 degrees. These suits should fit with a minimal amount of space between the suit material and the flesh. The body will warm the water inside and the suit material will insulate it from the cooler water surrounding the outside of the suit. If the suit fits loosely, more water will enter and it will take longer for the body to heat that water. A suit that fits too loose will allow cold water to flush out the water that the body had been heating up. This is a waste of the bodies heat and energy. If the suit is too tight, not enough water will be present to become heated. It can also prevent proper blood circulation and breathing respiration. A diver will get colder in a tight suit because of restricted circulation.

Wetsuits are generally made with a closed cell neoprene material. Small gas bubbles exist in this material. As a diver descends these bubbles become compressed as the ambient water pressure increases. The suit will become thinner the deeper the descent. This will lower the suits ability to insulate that warm water inside. The buoyancy from a wetsuit is also lost upon descent. This can create many problems which often escalate.

A drysuit is a suit that uses gases to insulate the divers body rather than water. Undergarments worn inside the dry suits are lofted (fluffed) with gases, creating the insulating barrier between the divers body and the water. These suits can compensate for the increase in ambient water pressure and it changes upon ascent of descent. A manual gas injection valve allows the diver to add gas as the suit compresses around the divers body upon descent. An adjustable exhaust valve will allow this gas to be purged from the suit during the ascent back to the surface. Education and practice are necessary in properly balancing a drysuit.

There are a variety of drysuit "shell" materials being incorporated in suit design these days. Choosing the right material should depend on the environment that the suit and diver will be exposed to. In public service diving or commercial work were contaminated water is present, decontamination of this material is important. Materials such as nylon or neoprene are very difficult to decontaminate due to their porous nature. Working divers may require a suit that has a higher puncture resistance. These suits are often heavier and not easy to swim with. A neoprene material that has had its gas cells smashed can be a good choice for colder waters. This material provides some thermal insulation and can allow a diver to minimize the amount of undergarment inside the suit. Neoprene suits take longer to dry. In warmer climates mold can grow on the inside. This material is porous and hard to dry of moisture from sweet or any other water intrusion. Laminate suits are generally lighter weight. These suits pack easily for travel, dry quickly and variety of insulation can be added. This include an electrically heated vests
weisel drysuit undergarmetsheat vest
Alterations made to Drysuits often include the addition of bellow pockets on each thigh. For men, a condom catheter overboard discharge unit, also known as a "pee valve" can be installed. The placement of these components is important. The pockets need to be within easy reach, without the need for the diver to hunch over to get to the bottom of things. They should also be attached in a fashion that they do not lay below the plane of the body. Bungie cord is added to attach items inside the pocket with a snap-bolt clip. This will prevent these items from pouring out when the pocket is opened.

The overboard discharge unit (pee valve) should protrude through the suit at a 45deg angle on either leg, and within hands reach. This will minimize snagging guide lines and other object . Its also important that the port doesn't rub the opposing leg while swimming. I prefer installing the valve on the left leg. This makes it easy to reach with my free left hand, since I often ride a scooter with my right. The pee valve hose should be shout and not easily kinked. This hose is typically ran from the leg up towards the belly button then back down, connecting to the appendage using a specialty condom. It's best to stand things up. This helps to keep the urethra open, allowing for good uninterrupted urine flow. The pee valve hose should have two check valve. One keeps water from backing up into the hose. The other helps balances pressure in the hose.
balanced pee valve billow pocket
Dry Gloves can also be added for colder dives. Although these gloves look bulking, once they compress in the water they are not so bad. The advantage of these gloves is that they keep your hands warm. The warmer the hands are, the more dexterity and feeling the hands will have. A soft glove liner in generally worn inside. These can be removed and dried if they were to get wet. A bulkhead seal needs to be present in the event that a glove might become dislodged of punctured.

Air or Argon, are common gas choices used to insulate a diver in a drysuit. These gases are injected into the suit via a valve located near the divers chest. When used properly, Argon can provide the greatest insulation due to the molecules large cross section diameter. This larger molecule reflects heat back towards the body and creates a dense barrier between the colder ambient water outside of the suit and the divers body. Argon is carried in a small compressed gas cylinder attached to the left side of the back mounted gas cylinders or to the side of a backplate. A diver who is breathing air will typically attach a low pressure hose to a first stage regulator and connect it to the drysuit. This eliminates unnecessary drag, weight and a snag points.
argom molecule dry suit inflation
As mentioned before, when we look at the balance of a diver, we can quickly see how top heavy they become. This is partially due to the heavy components such as the tank valve and 1st stage regulators sitting just above the shoulders. If we can add negative ballast to the lower torso area we will see a very different horizontal trim develop. A stainless steel backplate can help balance a diver by adding weight to the center of the body. These backplates offer a very stable platform to attach compressed gas cylinders. Nylon webbing secures this platform to the back and keeps it from shifting. Shifting of equipment can throw a divers balance and trim off while in the water.

Buoyancy Compensator Devices (BCD) are used to give extra lift to a diver. In a dive configuration using a wetsuit, buoyancy is lost as the diver descends. This is caused by the gas cells in the wetsuits neoprene material compressing. A BCD is used to counter the suits loss of buoyancy. A drysuit on the other hand looses buoyancy but gas is added to the suit, not the BCD upon descent. This is necessary for buoyancy and proper lofting of the suits undergarments. If a drysuit is allowed to overly compress the body a dangerous suit squeeze could "shrink wrap" the diver, preventing them from reaching important control items and sinking uncontrollably.

BCD's are also used to support a diver while resting on the surface. An overly weighted diver will rely on a BCD to lift them in the water.
This can become dangerous. If the BCD were to become damaged and unable to retain gas, a diver could sink unwillingly. Proper balance and weighting is of the utmost importance for a divers safety and making a dive an enjoyable memory.

A horseshoe or oval shaped BCD or "wing" can be added to a backplates with ease. These allow a diver to hover effortlessly like a hang glider in the sky. A variety of wing sizes can be used with the same backplate. Smaller wings (18-37 pounds of lift) are generally used for single tank diving. Larger wings (35-70 pounds of lift) are used for double tank configurations.

UTD single tank wingUTD double tank wing

It's important to maintain dive equipment and store it in a organized manor where it will not get damage. Remember, it's "life support equipment". Ozone can deteriorate your dive equipment. Try to keep it out of the sun and away from any vehicle exhaust fumes when ever possible.
John's garage w/dive gear
Scuba tanks come in many different sizes. These tanks have several uses. The large manifolded tanks are primarily used for deep or overhead environment dives. Single steel tanks which carry approximently 95 cubic foot (cf) of gas are often used when diving in a drysuit during shallower dives. I prefer Aluminum 80cf tanks when doing single tank dives in a wetsuit. Aluminum tanks generally have less negative buoyancy characteristics than steel tanks. They can be used as stage or decompression bottles and have good balance characteristic between full and empty. A few steel 72's are sitting around for pool dives. Aluminum 40's and 30's are primarily used for decompression mixture and pure O2. The 13cf and 6cf bottle will contain either air or Argon for drysuit inflation. Scuba Cylinder Buoyancy Characteristics are very important in properly balancing your overall equipment configuration. What ever the tank configuration may be, it is important to not overweight yourself with tanks.

Oxygen is required to sustain the human bodies metabolic needs. The air we breathe on earth contains approximently 21% oxygen. Only about 4-6% of this oxygen is actually metabolized at the cellular level, to create energy for life. A bi-product of this metabolic process is a gas called (CO2) or Carbon Dioxide. This C02 needs to be expelled from the body, otherwise it can cause a host of problems. Machines known as Rebreather's can remove the Carbon Dioxide from a divers respirations and introduce new oxygen to replace what had been used during that metabolic process.

While diving "open circuit" SCUBA, a dive inhales compressed gases, then exhale gases into the water. As we descend, the water pressure will increase. To inflate the lungs fully, a diver will need to inhale an equivalent amount of gas pressure, equivalent to the water pressure surrounding their chest. The deeper a diver descend, the more gas they will be required to inhale. Then they will dispose the exhaled gases into the water, creating bubbles. Some of this exhaled gas will still be good. If we can capture this exhaled gases, introduce new oxygen and eliminate the carbon dioxide then re-breathing these gases will be safe again.

The advantage of a rebreather is in gas conservation. Rebreather's are basically a loop design. Gas is delivered though a breathing hose from one side and exhaled to the other. From there the gas it is sent through a bag called a counter-lung then to a canister that uses a material to absorb carbon dioxide. New oxygen can be introduced into this breathing loop as needed, either by a computer controlled system or manually. Multiple oxygen sensor allow the oxygen level in the breathing loop to be monitored. Other gas mixtures called "diluent' can be added to flush the system and maintain proper oxygen levels. From this point on, gas it is sent to back to a counter lung before being "re-breathed". This is known as a "closed circuit" design.
mc90 rebreather
There are many designs of rebreather's but they all generally do the same thing. The machines can be complex, technical, and expensive. They require great attention and maintenance. Proper training is crucial. They are a good tool for dives in which gas requirements are outstanding. They are also beneficial for dive in which bubbles can create problems. The advantages of rebreather's are nice but come with the price of increased risk to the diver. Extensive training and practice are required to understand these risks and how to prevent them.
Canister dive lightback-up light
Dive Lights can be used in a multitude of environments. They offer needed light at night time or in dark environments such as night diving, and caves and shipwreck diving. They can also be used during the day. As diver venture just beyond the point of visibility, these lights serve as referencing tools for your buddy. They are also used as a signaling and communication device. In overhead environments such as caves and shipwrecks, lights are considered life support equipment. A good quality canister dive light can be costly. In extremely dark environments, a minimum of two redundant back-up lights must be added to the divers configuration. These are clipped to d-rings located on the divers chest for easy deployment.

If your going to spend the money on one of these, go for the gusto. Buy a good quality light. Think about a light with a canister that will hold enough lithium ion or nickel metal hydride batteries to power a hand held light head for at least twice the time you plan to spend underwater. This will provide you with "room to play" in the event of some unforeseen mishap.

There is a variety of light bulb technology on the market today. HID or "High Intensity Discharge" bulbs require a ballast that really pumps up the voltage to the bulb. These are expensive and bulky, but are still one of the most preferred lights by advanced divers due to there power conservation and good luminal intensity. LED lights are gaining in popularity as the technology advances in LED's and reflectors. One feature of LED is that they are less prone to breakage if dropped or jared. Another is they use low amounts of power. In my opinion, LED lights are quickly becoming the staple for divers and will eventually replace HID.

Dive Reels have many purposes. The are often used like a bread crumb trail during overhead environment and deep dives where it is imperative that you get back to the place where you started the dive. Wreck penetration and cave dives are just two examples of when dive reels are used. Spools are simplistic versions of a reel that typically carry less than 100 feet of guide line on them . These are used as "safety" spools for contingency if a "primary" guide line were to be lost or broken. They can also be used to "gap" a primary lines together or "jump" from one line to another. In open water diving, spools can be used to deploy a surface signal marker (or sausage) to the surface so boat support personnel can identify the divers location.
John's dive reels
A Diver Propulsion Vehicle, also known as "DPV" or "Scooter" can become an exciting way to enjoy a variety of diving activities. A skin diver might incorporate a DPV to make multiple pike dives, enabling them to spend more time underwater before having to motor back up towards the surface. A scuba diver can deploy a DPV at the beach and cruise for miles along the coast. Or descend upon a ship wreck and cruise around on a survey mission. Videographers can mount a camera to a turret attached to the top of a DPV and capture amazing footage. Exploration level divers use DPV's as tools for extended range dives. Loaded with lots of equipment, these technical divers are unable to swim against strong currents or swim long distances.
variety of scooter's X-Scooter
I have owned over 5 different DPV's and ridden many different models. I have found one scooter manufacturers technology to tower above the rest. This manufacturer is Dive Xtras. They are in the state of Washington, and build a series of DPV's called the X-Scooter. The size, weight, speed and burn time on all of their models is superb. I currently own one of their smallest model. It is called called the Sierra. This thing weighs a mir 35 pound and is roughly the same diameter as a aluminum 80cf scuba cylinder. With a depth rating of 600' it has a top speed of 182 feet per minute and an adrenaline pumping range of about 1.9 miles.

The X-Scooter diver propulsion vehicles are the most versatile DPV on the market today. Dive X-Tras builds several models, depending on how long and how fast you would like to go. Their smallest scooter is called the "Sierra". It is perfect for most beach and open water dives. The Sierra weighs only 35lbs and is about the size of an 80cf aluminum scuba tank. It comes with a variable pitch prop and a five speed shifting trigger on the handle. Its 24V nickel metal hydride battery pack can be swapped out with a lithium ion pack . This will produces approximently 2 1/2 hours of pure pleasure.
Dive Xtras Sierra X scootercool silloette
Dive Xtras has recently introduced the latest additions to their fleet. One of these is called the "CUDA". A little larger and heavier than the short bodied Sierra model, this 50 lbs. demon's 41VDC system has 8 speeds and is capable of pushing a diver an exhilarating 254 feet per minute with an impressive burn time of up to 284 minute. And the Cuda 850 offer a cruise range of 7.6 miles. Dive X-Tras has also recently introduced "The Fury". These puppy's are fast and include lithium ion batteries. Check them out at www.dive-xtras.com.

A lot of false claims have been made on the performance of several scooter out there on the market today. In 2008, a series of tests were performed in Lake Tahoe, Nevada USA on a variety of the top DPV performers. The test is called The Tahoe Benchmark and it appears as though it will continue in 2010.


Disclaimer:
This site is NOT intended to teach anyone how they should dive. It is simply reflecting on what I have done and continue to do and is my opinion only. Proper dive training should be gained before attempting anything involving the use of a Self Contained Underwater Breathing Apparatus (SCUBA).