Dive Right In Scuba's Ultimate Guide to Backmount Diving

Moving on from your open water class? Perhaps you have a few specialties under your belt or maybe you're looking to get into technical diving? Whether you're looking to understand more about diving in general or just in need of a refresher, this guide’s for you! Read on to learn all about backmount diving.

Let’s Get Philosophical

When diving right in (You know we can’t ever pass up that pun, it’s about brand recognition!) to the technical world it can be confusing to understand the “Whys.”

• Why do I have to switch to a different BCD?
• Why do we do things differently than in my open water class? 
• Why am I being told a lot of what my open water class taught me is now wrong? 
• Why is this happening?!? 

Well, if you're asking yourself any of those questions (in your head or out loud, we’re not judging) you've come to the right place.

A Brief History

I’m going to make a very long story very short. The Florida government sought to map underground cave systems to prevent pollution of the drinking water used by many residents. The Woodville Karst Plain Project (WKPP) was launched in 1990, with a group of divers tasked with mapping the systems. After years of exploration and some unfortunate accidents, they refined a diving methodology known as Doing It Right, or DIR.

The DIR System

Due to the high level of risk involved in technical diving, safety is the number one priority. DIR standardizes both equipment and techniques, allowing divers to develop muscle memory, thereby increasing safety and efficiency. 

For non-CCR (closed-circuit rebreather) dives, a set of back-mounted doubles with an isolating manifold is typically used with Hogarthian-style BCD and regulator configuration. For these extreme dives, even gear such as a backup mask, lights, spools, SMBs, and anything else you and your buddy carry are standardized. The benefits of this system allow you and your buddy to know where everything is located on yourselves and each other without having to think. This enables muscle memory to take over in an emergency situation, ultimately increasing the safety of the dive.

The DIR system can be applied to a wide range of dives, from single-tank open water to multi-stage cave dives lasting hours on end. The overarching principle is to keep things as simple as possible while remaining efficient and effective in achieving the dive's objective. By reducing potential failure points and maximizing safety, DIR helps you stay focused on the task at hand and explore the underwater world with greater confidence.

Equipment

In this section, we'll focus on the essential components of a backmount setup, including the backplate, harness, wing, and regulator.

Single Tank Diving

Single Tank and Getting into the Backplate World

The backplate and wing setup isn't just for advanced divers with double tanks – and that's part of what makes this system so great. It's incredibly versatile, allowing divers to start with a single tank configuration and more easily transition to back-mounted doubles when they're ready. No need to relearn a whole new system!

A backplate system consists of three main components: the plate, the harness, and the wing. Let's explore each one.

Starting With The Plate

There are different materials available, with steel and aluminum being the most common. You'll also find options like carbon fiber or soft plates (made of stiff fabric and semi-rigid plastic). The backplate features various slits, notches, and holes to accommodate a diver's specific needs. 

For those who love to travel, lightweight aluminum or soft plates are the go-to choice. Aluminum plates can have large cutouts to further reduce weight.

You'll also find backplates in different lengths to suit your body size and comfort preferences.

And of course, there are plenty of accessories! A common one is a backplate pad, sometimes with a built-in pocket for extra storage. Another option is a weight covering that sits on the back of the plate, eliminating the need for a weight belt when diving with a single tank.

The Harness is Next

Harnesses range from simple one-piece designs to complex systems with numerous pieces and components. If you want to keep it basic and easy on the wallet, then a one-piece harness is the way to go. You can also find more complex harnesses with chest straps, protective or comfort pads, quick-release shoulder buckles, adjustable shoulder straps, multiple clip-off points on both the chest and waist, and much more. Depending on the harness, a crotch strap may or may not be included, but one is typically recommended. The Hogarthian style is a one-piece harness, with one D-ring on each shoulder strap, a D-ring on the left side of the waist strap, and a crotch strap with one D-ring in the front directly below the waist strap loop and one below the back of the plate.

And That Leaves The Wing

Wings typically range between 20 and 32 lbs of lift for a single tank setup. There are three main things to consider: color, inflator, and dump valve. Color is the most obvious choice and entirely dependent on personal preference. The inflator hose comes in different lengths. The other big difference is whether the inflator has a rapid exhaust feature. This allows the diver to pull the inflator hose down and release gas from the elbow of the inflator.

The Single Tank Adapter

The single tank adapter, or any variation of it, is used to mount the tank to the backplate and wing. This is vital, you wouldn’t want your tank falling off your back! An adapter is typically a steel or aluminum channel or bent plate that allows for two cam bands to be laced through, then bolted to backplate through the wing. This creates a connection between the tank and the backplate.

Some divers, particularly travelers, prefer to ditch the adapter and simply web the cam bands through the plate and wing. This is also helped by some newer wings, which come with stabilizing rods that run along the attachment grommets on the wing, creating some stabilization.

However, I have found in a pinch that a wing without these rods or a single tank adapter, only using cambands does work, although I would not recommend it as a permanent solution. 

The Single Tank Regulator

Starting in your open water course, you probably used a yoke first stage with a primary second stage on a short hose and a yellow backup regulator (octopus) on a long hose. It was likely also connected to a console with a pressure gauge, computer, depth gauge, and/or compass, or some combination of those options.

Note: There is absolutely nothing wrong with diving the same setup or something similar to what was just described. What follows below is simply another variation of a regulator configuration.

The more or less standardized long hose configuration follows in its "big brother" double tank setup's footsteps. It features a first stage connected to a backup second stage on a short hose with a bungee necklace that hangs below the neck. The primary second stage is on a 7-foot-long hose looped down under the armpit, across the chest, and then looped over and around the neck.

The reason for the primary regulator being on the long hose is the ability to donate a regulator you know is working to an out-of-air diver. A regulator a diver hasn’t used in a while, and doesn't know for certain that it will work, given to an already panicked out-of-air diver will likely cause them to tear the regulator out of your mouth. Instead, simply donate the regulator you're using, then switch to your backup that is readily available on the bungee necklace.

The other alteration is the abandonment of the console. Instead, a pressure gauge without a boot or anything else is used. A clip is attached with a line (string) to the SPG, allowing it to clip to the left waist strap D-ring. The computer and, if applicable, the compass are then wrist-mounted to allow the diver easy access at all times.

Diving Doubles

Just because you double the tanks doesn't mean you're doubling the complexity! It is more complex than a single tank, and care should be taken (as always) to ensure that both you and your equipment are ready for the dive you will be doing. Always consult a trained professional when diving new equipment configurations. 

Tanks

Tanks are a bit different in the doubles community. They are banded together with two metal bands (aptly named "bands") and the valves are connected with an isolator manifold in the middle. This offers several advantages. If one regulator fails for any reason, you can close that post and still have access to both tanks. In the event of a tank valve failure, you can simply turn off the isolating valve and breathe off the good regulator.

Doubles  Regulators 

Doubles regulators are a new necessity when diving doubles. You move from one first stage and two second stages to two first stages and two second stages. Divers distinguish between the two as "Right and Left" or "Right Post and Left Post" when assembling the regulators and preparing their equipment at the dive site. "Right post" refers to the diver's right side when wearing the tanks. While it's common to use a 5th port to make hose routing more streamlined, it's not mandatory.

• Right post: 7ft long LP hose with the primary regulator with a clip and a BCD quick-disconnect inflator hose.
• Left post: 26-32in short LP hose with a backup second stage on a bungee, HP hose with a clipped pressure gauge, and, if applicable, a drysuit inflator hose.

Doubles Wings

Doubles wings boast a larger lift capacity, typically ranging from 40-60lbs, with some extreme models lifting 80lbs. With doubles, you no longer need a single tank adapter, and the backplate sits directly on the bolts of the tank bands, as long as they are properly assembled. Colors are less common when it comes to doubles wings, but they can still be found. The big difference to consider is whether you want a single or dual bladder wing. The main reason to choose a dual bladder wing is to achieve a redundant buoyancy control system without the need for a drysuit, which is particularly relevant for tech diving in a wetsuit.

Backplates

Backplates remain the same. That's one of the benefits of diving a backplate and wing system: no matter the dive, you maintain muscle memory and don't have to constantly re-learn how to dive.

Stage, Decomposition, and Bailout Bottles 

Whether you're extending your bottom time with a stage bottle, accelerating your decompression time, using a bailout for a solo dive, or simply wanting to have a redundant air source to increase your safety factor on the dive. Learning how to sling a tank is important.

Valves

Valves for deco and stage bottles are all the same, and conveniently, they're the same ones you use for single-tank diving. When the bottle is facing you, the hand wheel is on the left. The valves are typically DIN, as are the regulators, but you can use a yoke in a pinch.

Note: If a diver is side mounting deco/stage bottles you may want right and left-hand valves. (more on that later) 

Regulators 

Regulators for stage and deco bottles are also similar. They consist of a DIN first stage, typically with a swivel (though fixed first stages can be used), connected to a short 6-inch HP hose and pressure gauge. A second stage is attached to a 30-40 inch hose with a clip and a 90-degree angle adapter. While specialized deco/stage regulators exist, many tech divers prefer to build their own.

Another Note: Button gauges can be used but are generally not favored as they don't provide enough precision when planning and executing dives to accurately determine tank pressure.

It is common to see the pressure gauge "tied up." Using string, you can wrap the SPG around the back of the regulator, allowing the diver to see the gauge at all times. This also enables one-handed deployment of your decompression bottle.

Yet Another Note: While some divers color-coordinate their regulators (green for pure oxygen, yellow for high oxygen nitrox mix), it is never safe to rely solely on color to identify the gas mix. Also, color-coding can limit your regulators to a single mixture or tank, and when something breaks or needs replacement, a specialized hose or regulator needs to be replaced and can't be easily swapped from a spare. For these reasons, many divers choose to forgo colorization.

Tank Hardware 

The rigging on a stage or deco bottle is designed for easy handling in and out of the water. A rope or one-inch webbing is wrapped around the tank neck, with the first clip positioned at the start of the flat cylindrical surface right below the dome. The rope is then fed through a piece of tubing where a worm clamp or cam band is placed. Next, a 2-4 inch length of rope is added, ending with another clip. One or two hose retainers of the diver's choice are placed under or over the other tank hardware.

The rope/webbing should be tight against the cylinder. If left on the tank for long periods, it may loosen, so some minor adjustments might be necessary. The two clips should form a straight line down the tank, placed directly in front of the tank valve.

Hose retainers can be purchased at your local dive shop or online, but a favored alternative is to cut 1-2 inch rings from an old car tire inner tube and then wrap and tie a piece of rope to them, allowing for easy use when wearing thick dry gloves.

Tech Tip: While many use one-inch webbing, a rope is often preferred as webbing can twist, making it more difficult to clip. Webbing also requires additional hardware like one-inch tri-glides. The simplicity of knots in a rope makes it a favorable option.

The fixed rope allows the diver to easily carry a stage bottle when out of the water, and the sturdy clip attachments allow the diver to enter the water with the tank already attached, without worrying about something breaking.

A Little  Note When Diving With a Slinged Bottle: The method above is the most common, however, depending on the situation you may want to change things up. One interesting method to point out is to sidemount the stages. This is done by placing a bungee through a hole in the backplate, one on each side, and rigging the bottles like sidemount bottles. View our sidemount guide for more information. Also, when carrying a bailout bottle in a single tank, oftentimes divers clip the tank across the body so as to not imbalance the diver too much. 

Lights

Lights are crucial for all kinds of diving, whether it's to illuminate the nooks and crannies of a reef or simply admire the colorful fish. However, they become absolutely essential for both signaling and visibility when you venture into technical diving. There are two main types for technical diving: primary and backup lights.

Primary Lights

Lights come in two main varieties these days: canister and handheld. If you're using a handheld light, you'll need a way to mount it securely. The most common choice is a Goodman handle, made of metal or heavy-duty plastic. The Goodman handle fits over your fingers and rests on the back of your hand, providing a stable platform for the light.  One or both sides of the top plate are attached to a bottom plate that sits in your palm. This allows you to easily put on and take off the light, either by a snug fit or by lightly gripping the bottom bar.

If you're using a canister light, the canister is typically mounted to your right hip on the waist strap.

Another common option is the soft hand mount. This consists of a hard plastic or metal top plate, covered or attached to a neoprene sleeve that you wear on your hand. These systems often require you to fasten the hand sleeve securely before diving, and it can be tricky to adjust velcro or buckles underwater.

Secondary Lights

Secondary, or backup lights, are essential in case your primary light fails. Divers can also use secondary lights as their primary light on non-overhead recreational dives. For technical diving, two secondary lights are placed, one on each side of the diver's shoulder straps.  A clip on the light attaches to the shoulder D-ring, and the bottom of the flashlight is secured to the shoulder strap with a rubber band or bungee loop.

Tech Tip: A small bungee loop protruding only ¼ inch from the shoulder D-ring allows you to clip into both the hard D-ring and the loop. This keeps the light clip out of the way, high up on the D-ring, making it easier to use the shoulder D-ring when needed.

Even on recreational dives, I like to place a light on my shoulder strap as described above. This saves pocket space and prevents me from looking like a Christmas tree!

Exposure Protection

You didn’t think I’d forget about what you’ll actually be wearing underwater, did you? Let’s take a close look at exposure protection, the different types, and what to know when you’re suiting up.

Wetsuits

Wetsuits are a popular choice for divers in warm-water destinations like the Caribbean, where temperatures remain comfortable year-round. Ranging from shorty 2mm suits to full-body 7mm suits or even semi-dry suits, wetsuits are often preferred when conditions allow, as they offer a reduced task load compared to drysuits.

Drysuits

Drysuits provide divers with a wider temperature range, as their insulating properties come from the diver's undergarments. You can wear anything from a simple sweatshirt and sweatpants to a multi-layering system designed for sub-freezing temperatures.

• Trilaminate (trilam) and neoprene are the two most common materials used for drysuits. Unless a diver is planning on diving in close to or sub-freezing temperatures, or in particularly rough environments or conditions, trilam is often favored as it is less buoyant and allows for more flexibility when properly sized.
• Latex or silicone are the most popular choices for neck and wrist seals, with neoprene seals available for those who prefer their warmth and durability. Different styles and shapes of seals can be found for each material.

Boots

Boots are another key consideration when it comes to drysuits. The two typical options are shoes or socks. All boots are usually made of neoprene with some type of sole. However, other fabrics with a light sole can also be found. Some divers prefer socks and will then buy oversized shoes or specialized drysuit rock boots.

Dry Gloves

Dry gloves are used when finger dexterity is important in cold water (finger dexterity is always important!). In the Great Lakes, a drysuit is almost always accompanied by a dry glove system. There are many systems on the market, including pressure-fit and twist-on styles, with oval or circular wrist rings, and pullovers.

Heated Vests

Heated vests and heated suits are becoming increasingly popular. Several companies manufacture them, with some designed to replace your undergarments and others meant to work in conjunction with them for added warmth. A battery is required and is often wired through the diver's inflation valve, which may necessitate a new valve or a modification kit.

Auxiliary Drysuit Inflation

Auxiliary drysuit inflation is not uncommon and becomes necessary when getting into trimix or heliox classes and dives. A small (typically 6cf) cylinder is used to inflate your drysuit. It's mounted to the backplate with either two straps that bolt into the backplate or one strap and a bungee. A small, specialized drysuit regulator is often used as they have a smaller profile than your typical first stage. These regulators are often equipped with a button gauge to give you a general idea of how much gas is left and when the bottle needs refilling.

• While not as common anymore, I'm a fan of using argon for drysuit inflation as it keeps you warmer than typical air. The bottle is mounted upside down, allowing the left hand to easily reach the valve and turn it on or off.

For our science-minded audience, the chemistry behind diving with different gasses is quite interesting. In simple terms, the lighter the gas in the drysuit, the faster it exchanges heat, and the cooler your body gets. When diving with helium, the light gas exchanges heat rapidly, making it necessary to use another gas for suit inflation. Typically, air is used these days, but argon is a heavier element, resulting in less heat exchange and keeping you warmer. Additionally, argon is significantly cheaper than a heated vest or suit system.

Hoods

Hoods are critically important when diving in cold water and can even be helpful in warmer water. Most heat loss, particularly in a drysuit, occurs through the head. A thick 7mm hood with a bib is often used, as latex dry hoods can easily tear, puncture, or simply fail to seal properly. If your drysuit has a "warm neck" – a piece of neoprene sewn around the neck over the latex, silicone, or neoprene collar – you can tuck the hood bib in for even more insulation.

Overhead Environment Considerations

Reels and Jump Spools

Reels and jump spools are essential for cave diving and wreck penetration, but they can be quite bulky. When gearing up, the rear crotch D-ring is a convenient place to store them until needed. Remember to use the correct line for your reel or spool. Wreck line is typically thicker and more abrasion-resistant, as it may come into contact with rougher surfaces than those found in most caves.

Lights 

Three lights are required for cave diving: a primary light and two backups. The two backup lights are often clipped, one on each side of the diver, to the shoulder D-rings and run down the shoulder straps with a bungee loop on the harness to keep them secure against the body. If you're using a canister light as your primary, it's typically mounted to the diver's right waistband, with a buckle or other clip mechanism to keep the canister tucked in towards the backplate.

Drysuit Inflation 

Drysuit inflation is another important consideration for cave diving. Depending on the environment and cave system, you may need a larger cylinder than usual, typically an aluminum 13cf, as a smaller bottle might not provide enough gas if the cave changes elevation throughout your dive. A larger bottle also comes in handy when planning longer trips, particularly when diving with argon or when a fill station isn't readily available.

Diver Propulsion Vehicles (DPVs) or Scooters

Always remember to receive proper training from a reputable instructor before using DPVs on your own.

Recreational DPVs

Recreational DPVs are a great way to increase your range, though they often have relatively short runtimes of 30-90 minutes and require two-handed operation.

Technical DPVs

Technical DPVs are built to last for hours and allow the diver to be towed by the scooter instead of having to use arm strength to hold onto the vehicle. A tow strap is connected to either side of the DPV's handles and attached via a clip to the diver's front crotch strap D-ring.

Stage/Deco Bottle Adjustment with a DPV

Stage/deco bottles might need a slight adjustment when using a DPV. If the bottom clip of the stage kit is left slightly longer than necessary, the bottle can find its natural slipstream when being towed. When swimming, the excess rope length is used up by wrapping the clip around the point of the worm clamp to ensure a more streamlined experience.

Managing Multiple Decompression or Stage Bottles

If you're using more than two decompression or stage bottles, a leash made of a small piece of rope and tubing can be beneficial. This allows the diver to clip their tanks to the leash, and then clip the leash to their waist D-ring, keeping them out of the way when not needed.

Primary Light Considerations

Another benefit to a Goodman handle is the attachable thumb loop. Not often needed but can be helpful when scootering as the scooter handle may not be conducive to the normal light placement. 

Towing

Towing a diver is covered in your DPV class, but as a quick reminder, the diver being towed will hold onto the crotch strap of the diver in front of them and get as close as possible to reduce drag.
Towing other equipment typically involves clipping the item to the back crotch D-ring.

Classes

While all training agencies differ slightly, they typically follow a well-defined hierarchy of depth and skills. For example, if you follow SDI/TDI's classes from open water to advanced trimix, it looks something like this:

Embrace the Backmount Adventure

Backmount diving offers a world of possibilities, from the simplicity of single-tank exploration to the technical challenges of deep dives and overhead environments.  Whether you're just starting out or looking to expand your diving horizons, mastering the backmount configuration is a rewarding journey. Remember, with the right gear, proper training, and a thirst for adventure, you'll be well on your way to unlocking the full potential of backmount diving and experiencing the underwater world like never before.

Dive safe, dive smart, and always remember: the best dive is the one you come back from with a smile on your face and a story to tell!