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Scuba Gear FAQs
Scuba Gear FAQs | Scuba Gear FAQs |
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| Written by Administrator | |
| Tuesday, 31 July 2007 | |
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We get asked on a regular basis what gear we recommend, so we thought we'd provide some basic information on the website. We're starting with a couple of important pieces or gear (and the ones that we're asked about the most). We'll build these pages as we have time to put the information together. The information we provide here is our opinion. It is based on our experiences and what we have learned over our years of diving. We will try to support everything we say and be as unbiased as we can be. If you have any additional information or comments on gear, please e-mail us at This email address is being protected from spam bots, you need Javascript enabled to view it and let us know. We will post it here. Buoyancy Compensators There are a few different types of buoyancy compensators available on the market today, all with different features. The four we can readily think of are horse collars, jacket-style BCDs, back-inflate BCDs, and backplate and wing (BP/W) systems. The horse collar was used in the beginnings of diving. Typically the diver would have to orally inflate the collar to compensate for buoyancy changes caused by pressure. There are still some horse collars available on the market. Most are used primarily for snorkeling. Some do have the capability to attach a low pressure hose to them to automatically inflate with tank air. These devices were great in their day and still have their place today, but diving isn't that place for most divers. Typically, it's something you'll see vintage gear divers using. They're rather bulky and not too easy to use. They create a lot of bulk around your neck. And when used on the surface, will keep you afloat by pulling your head out of the water. Not exactly the best way to stay afloat. You won't find many, if any, in stores or on the Internet new. Most of what you'll find in the horse collar BCD is in vintage scuba sales.  Horse collar The most common type of BCD seen at most dive shops and resort locations is the jacket-style BCD. There are various reasons for this, which we won't go into here. The jacket-style BCD is likely the style of BCD you have used in open water training or on resort dives. They are typically the least expensive BCD you will find (although some can be quite pricey nearing $1000). The main disadvantages we see to them is their bulkiness and squeeze factor. Jacket-style BCDs contain a bladder that wraps around your torso. Usually squeeze isn't that much of a problem underwater because you shouldn't be inflating your BCD so much that it squeezes you there. The squeeze issue comes up when on the surface. As you inflate the BCD, it hugs you. If you have to inflate it fully to stay afloat, then it can squeeze you. Underwater the issue is drag. When you inflate the bladder, the BCD grows in size. This creates more drag in the water, reducing how streamlined you are and creating more work to move through the water. The design of the jacket also puts a lot of unnecessary bulk rignt in front of you.  Jacket-style BCD The back-inflate BCD is becoming a little more popular, but can still be difficult to find. Back-inflates usually start around the $300 range and go up from there. Some can cost over $1000. Back-inflates take the bladder and put them behind you. You still have straps that wrap around the front of your torso, but the only thing that inflates now lies behind you like wings. Back-inflates don't create as much drag and definitely don't create any squeeze. Some people claim that it is difficult to stay head up on the surface in a back-inflate. These people will tell you that the back-inflate will push your face into the water. This is NOT true. We started diving back-inflate BCDs immediately. In fact, we bought our gear and used it for our open water checkout dives. We have never had a problem with the back inflate pushing us forward. The tank placement and leverage of your legs in the water keep this from happening. It's actually quite relaxing to float at the surface in a back-inflate BCD, and it's even easier to lay on your back in one. A disadvantage to these is that most still have a lot of bulk in the waist and shoulder straps.  Back-inflate BCD A backplate and wing system, in our opinion, is the best set up you can get if you want to dive backmount. They are compact, streamlined, require less weight, and require less energy to move through the water. They are also great value. BP/Ws can also save you a lot of money, both now and in the long run. A decent system will cost about $400. BP/W systems are basically modular back-inflate BCDs. The bladder is on your back and is called the wing.  Wing Wings come in horseshoe or donut shapes. What that means is the air can move from one end to the other through only one route (near your head) with the horseshoe shape or all the way around the circumference of the wing with the donut shape. The wing attaches to a backplate, which is made from either aluminum or steel, with bolts.  Backplate The bolts are usually attached to a single tank adaptor (STA) used to hold single tanks firmly in place along your spine.  Single Tank Adapter The backplate is made from different materials depending on your weighting needs. Aluminum plates are usually 2 pounds and used in tropical warm water environments that require little to not weight. Steel plates range from 4 pounds to 17 pounds and can be used in any environment with the weight of the plate dependent on the type of exposure suit required. The plate is then strapped to the diver with a one-piece harness (Hogarthian harness) or a manufactured harness.  Hogarthian harness  Harness The harness is very minimalistic and puts very little on the front of the torso. This means less bulk, which means an increase in streamlining. It also means less weight needed because you don't have all the nylon material found on jacket-style and back-inflate BCDs that create positive buoyancy that need to be counteracted with weight. What all this means is that you will need less weight in the water. Less weight means less drag, and less drag means less work at diving. So the end result is less air consumption and longer dive times. The great thing about BP/Ws is the modularity. You can change out the backplate or harness or wing, but don't have to change all three. We use the same backplate and harness with our single tank wings and our double tank wings.  Sidemount System The sidemount system is our preferred set up for diving. In this configuration, the tanks are positioned along your sides instead of on your back. There are several advantages to this. First, the weight is removed from your back and place along the plane of your body. This helps balance your body more easily in the water. Unlike in a backmounted system, it is very difficult to become unstable and flip yourself over in a sidemount system. However, you still have enough control to rollover onto your back in a controlled manner. Sidemount is also more streamlined. Properly positioned cylinders are tucked under your arms exposing less surface area of the cylinders to the forward force of movement through the water. Sidemount also keeps you from having to carry heavy cylinders on your back on land. Simply place the cylinders on a truck cart and roll them to the water. The cylinders are then attached to your sidemount rig in the water. While there is a little more task loading in that regulators must be alternated during the dive to manage the gas supply appropriately, it is a minimal amount of extra work. On an average dive regulator switches should only have to be done 3-4 times. Finally, there is no set configuration in sidemount rigs. Sidemount divers modify their rigs to fit the type of diving they are doing. It's not likely you will find 2 sidemount divers with identical configurations. Even we have slight differences in our rigs! There are a couple of different basic fin designs - paddle fins and split fins. Paddle fins, such as the following, were one of the original basic designs.  Paddle fins (typically used with drysuits) These are solid, stable fins that provide a lot of power, especially for someone in a dry suit, diving in doubles, or diving with stage tanks. They provide precise control once you get used to these fins and practice different fin kicks. They are truly versatile in that they are efficient fins whether you are doing a frog kick, flutter kick, helicopter turn, or backwards fin kick. One of the downsides, or upsides (depending on how you look at it) to these fins is they are heavy fins that are negatively buoyant in the water. This could be useful in a dry suit, but could be a big disadvantage to someone diving in a 3mm wet suit or shorty. In fact, we only dive with our Scubapro Jet fins when in our 7mm wet suits or dry suits. As time moved on, manufacturers decided to try to make fins more efficient. By doing this, they decided to add channels to the paddles fins.  Paddle fins This made the fins more pliable and able to channel the water through them during kicks. This works well with standard open water flutter kicks, but isn't very efficient when doing any of the other kick styles. The channels also reduce the stiffness of the fins, making these fins inadequate for divers in dry suits, diving doubles, or with stage tanks. Depending on the manufacturer and fin model, you can find anywhere from one channel to four channels in these types of fins. Another adaptation that was made to fins was the split. Rather than just put a channel or four down the paddle, manufacturers decided to cut the paddle down the middle.  Split fins The idea behind this is the fin becomes more efficient by the propeller motion of the split paddle. These fins can be highly efficient when used with a flutter kick, the kick they were designed to be used with. However, they do not allow for much control when attempting to frog kick or backwards kick with them. Different divers like different fins. We prefer paddle fins, specifically the Jet fins, but that does not mean you will. Our advice is to try different fin types and see what works best with your diving style. Keep watching here for an explanation of different fin kicks. |
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