Back when I was a regular diver- cave divers and to some extent, technical divers were taught to carry their cylinders around their hips after they were competent enough in diving with twin-set back-mounted tanks. However the term ‘side-mount diving’ became prevalent in the diving community only recently.
Fast forward to today, side-mount diving is a common household (or dare I say scubahold) term not only among the tec and cave divers but recreational divers too.
PADI’s addition of sidemount diving as a distinctive specialty course in their certification arsenal only flamed its popularity further. If you’re a recreational diver willing to dip your toes and try out sidemount diving, this might just be the article for you to get familiar with the essentials of side-mount diving.
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What Is Sidemount Diving?
Sidemount diving is a scuba diving configuration where a diver wears their tanks on their sides instead of on their back, as is typical with the more common back-mounted configuration. In side-mount diving, the tanks are attached to the diver’s harness or buoyancy control device (BCD) on either side of their body typically with bungee cords running above and below the torso.
Ideally, a side-mount configuration offers the highest possible vertical trim for a diver which helps in better streamlining while diving.
How to Get Started with Side-Mount Diving?
Unlike regular back mount recreational diving where you can dive with a 1-day resort dive course, certification is mandatory for sidemount configuration.
To qualify as a PADI side-mount diver you need to attend a two-day certification program that includes four dives using side-mounted cylinders. You have to be certified in Open Water (although I would personally recommend being at least Advanced Open Water certified) and at least 15 years of age.
For the recreational, non-decompressing diver this is a great way to dive. You can choose what size of cylinders you wish to dive with, but whatever your choice, safety is increased by having additional gas and bail-out options – something that many recreational divers attempt to provide with the application of the three-liter pony system.
The PADI side-mount course has been endorsed by the PADI DSAT Tec Rec organization, which means that side-mounts can be used on all the programs in the Tec range.
6 Convincing Reasons to Try Side-Mount Diving
While side mount is a great way of diving within normal recreational limitations, there is a huge plus with this program for those divers who wish to extend their diving beyond these limits.
1. Air Supply Renundancy with Extra Bail-Out Options
First on the list would have to be safety. Since sidemount configurations do not come with a manifold, you are free to switch from one tank to the other (or side-mounted deco bottles if you have any) in case of valve failures without going through the hassle of manifold isolation.
Simply put, diving with a side-mount system means that you have another set of air bail-out options at your disposal, so in the event of a failure on one tank, you always have an adequate backup even if you lose sight of your buddy during the dive with no means of sharing air.
Now don’t forget to stick to your dive basics while switching air supply. In the event of valve damage or freeflow, don’t panic but slowly ascend to a decompression stop in conjunction with your buddy.
2. Increased Buoyancy and Trim Control
The second on the list would probably be buoyancy control. Horseshoe wings and twinsets can take a bit of getting used to. Using the side-mount system, buoyancy control is, quite frankly, a doddle and you will be gliding like a champ in no time.
For those of you with a penchant for crawling through small spaces and wreck penetration, side mounts offer you improved streamlining. With sidemount configuration, the top of your profile is your head, not your tank manifold which allows for the perfect trim.
If you want to increase your streamlined profile even further you can even unclip the rear of your cylinders and hold them in front of you.
3. Side Mounts Demand Less Flexibility
One of the biggest downsides of back mount twin-set configuration is the lack of flexibility you’re left with. In the event of a tank shut-down when your tank is leaking or a valve is non-functional, you have to turn your head diagonally up backward to identify the problem and mitigate it. This not only puts a strain on your neck and spine in the long term but also breaks your streamlined form.
Some divers might opt for an inverted back mount where the twinset’s valves manifest faces away from the head. This might get rid of straining the neck but they still have to feel their way around to pinpoint the problem in their tank valve or manifest without any visual aid. Unless you’ve memorized every square inch of your tank (which is a downright impossible feat with every set of tanks you rent for each new dive) this isn’t a sound solution.
Here comes the sidemount configuration to the rescue. With sidemount, there’s no more reason to twist your spine backward or sprain your neck during a tank shut-down, you can simply look down or sideways at your tank, identify the problematic one, and shut it down.
If you struggle with the weight of twins on your back or have any form of back pain then you will appreciate side-mounts and the dreaded ‘twinset stoop’ will be a thing of the past.
4. More Bottom Time with Less Gas Consumption
Since there’s less underwater drag due to better trim and buoyancy you have to expend less energy while carrying a side mount compared to a back mount. Naturally, less consumption leads to more relaxed breathing that significantly lowers your air consumption. So, you won’t need to break a sweat about air conservation during your dives as much.
Result? With side-mount, your bottom time can increase by up to 30%! Not a deal I would be passing on for sure.
5. Hose Routing Is Easier
With all the hoses running all over the body, some connecting to your tanks, some to your BCD, some to your deco bottle, and some to your spare regulator managing them can become overwhelming for scuba divers.
Without proper hose routing, you are at greater risk of getting yourself into a form of underwater entanglement with your hoses rather than stray fishing nets. Sidemount configuration reduces the underwater wiring problem to a great extent.
With all the dive tanks and redundant air supplies attached to your side, the only hose going over your back is the one connecting to the power inflator of your BCD, the rest of them are routed around your armpits and in a way stay strapped on to your front delts. This kind of under-the-armpit hose configuration is the least intrusive.
6. Better Cushioning for Your Tank Valves
With sidemount configuration, your delicate tank valves are located right behind your armpits and are better cushioned from external damage than when in the back mount position.
No more straining your neck to pin your head to your tank manifold or valves while entering underwater structures. You are left with a greater range of head movement.
Necessary Gear Adjustments for Side Mount Diving
You don’t need a radical overhaul of your driving gear to indulge in side mount diving the only change required is a bit of tweaking in your BCD system.
It requires a harness and wing with rails at the rear, but the good news is that the benefits of side-mount diving have been recognized and there are several manufacturers offering harnesses and wings specifically designed for side-mount.
What I can personally recommend is the Hollis SMS75 Complete Sidemount Harness BCD, it’s tailored specifically for sidemount configuration. You can even use it for traditional back-mounted twins and single tanks.
Alternatively, if you want to adapt your existing wing and harness system you can add a butt plate with rails to the backplate, so you don’t necessarily have to spend a fortune. The rest of the gear you need for side-mount diving will probably find you have already, just in a different configuration.
Drawbacks of the Sidemount System
Don’t let the looks deceive you. As a former Trimix instructor with many years of twin set experience, I was as skeptical as probably many of you are when I first looked at the side-mount system. Surely the extra gauge on the second cylinder would be an additional failure point; how would I possibly manage without the extra gas that the manifold offered me?
The fact is that for every question I raised, there were solutions.
I think the only disadvantage that I couldn’t offer a solution to was the need to look at two air gauges rather than one.
Give It a Go, You Won’t Be Disappointed
There is a possibility that side-mount diving might be just too different for many old-timers. It is a different method of kit configuration and a different method of gas management.
Old habits die hard in the diving community, but the best I can do is encourage you to give it a go. It offers some significant advantages and works well for any level of diving, both recreational and technical. It is growing in popularity and many believe it could, potentially, overtake twin-set diving. So why not try something new? Go on, have a bit on the side for a change.
