Tec Sidemount: Is This Technical Course Right for You?

There's a moment early in a Tec Sidemount course when a diver looks down at two independent cylinders slung along their hips instead of one strapped to their back, and something clicks. Suddenly redundancy isn't theoretical, it's right there, clipped to a rail, breathing from whichever regulator you choose. At Diving Academy in Reading, Tec Sidemount is one of the courses we get asked about most as spring approaches and divers start thinking seriously about where their training goes next. This guide walks through exactly what the course involves, who it suits, and how it fits into a longer technical diving journey.

What Is Tec Sidemount?

Sidemount diving began as a way for cave divers to squeeze through tight passages that a back-mounted twin-set simply couldn't fit through, but it has grown into one of the most popular configurations in recreational and technical diving generally. Instead of one or two cylinders on your back, you carry two independent cylinders clipped along your sides, each with its own regulator and pressure gauge. Our Tec Sidemount course teaches you to configure, trim, and dive this system safely, moving from basic buoyancy and positioning through to full gas management between two entirely separate supplies.

The appeal isn't just streamlining or comfort, though both improve noticeably once you've dialled in your rig. Sidemount gives you genuine redundancy, so if one cylinder or regulator develops a problem, you isolate it and switch to the other, completing the dive on a fully independent gas supply. That principle sits at the heart of technical diving, and it's why sidemount has become a foundational skill for divers heading toward decompression diving, cave diving, or extended wreck penetration.

Who Is Tec Sidemount For?

We see three types of diver come through this course. The first is the technical diver in progress, someone working through our Tec Academy pathway who needs sidemount as a stepping stone toward more advanced certifications. The second is the recreational diver who has heard about sidemount's comfort and back-friendliness and wants to try a genuinely different way of diving, without necessarily chasing deeper technical qualifications. The third is the travelling diver, often someone who dives regularly abroad and wants the flexibility of a configuration that works well from small boats and awkward shore entries alike.

Sidemount also suits divers carrying old shoulder or back injuries better than a heavy back-mounted rig, since the weight sits lower and more evenly distributed. Instructors and dive professionals often adopt it simply because it's kinder on the body across a long working day underwater.

Prerequisites and What You Need Before You Start

To join our Tec Sidemount course you'll need to be a certified Advanced Open Water Diver, or equivalent, aged 18 or over, with at least 25 logged dives. You don't need any previous technical training, and in fact this is often the first technical-style course divers take, precisely because it builds the foundation skills, such as trim, buoyancy, gas awareness, and task loading, that later technical courses assume you already have. If you're coming from our Scuba Academy and thinking about the Tec Academy long term, this is the natural entry point.

You don't need to own sidemount-specific equipment before you arrive. We can fit you with a demo harness for the duration of the course while you decide whether to invest in your own rig, and our instructors will talk you through the pros and cons of the main systems on the market based on the kind of diving you actually plan to do.

What a Typical Course Looks Like

Day One: Configuration and Confined Water

The course opens in the classroom and the pool. We start with harness setup, covering how to clip, route, and balance two cylinders so you're not fighting the rig all dive. From there it's confined water work, including buoyancy checks, trim, basic propulsion techniques adapted for sidemount, and your first gas-switching drills. It looks fiddly for the first hour and then, for most people, it just clicks.

Days Two and Three: Open Water Dives

With the basics comfortable, we move into open water for a series of dives that build in complexity. You'll practise valve drills, out-of-gas scenarios using your second independent supply, S-drills, and general task loading while maintaining horizontal trim and neutral buoyancy. By the final dive most students are managing their gas switches without conscious thought, which is exactly the point, since the configuration should fade into the background so you can focus on the dive itself.

What You'll Actually Learn

Beyond the mechanics of clipping and switching cylinders, this course teaches genuine gas management discipline. You'll learn to plan your dive around two separate gas supplies, track consumption on each independently, and make real decisions about when to switch, when to isolate a problem cylinder, and how to turn a dive safely with reserve gas intact on both sides. You'll also refine trim and buoyancy skills that carry over into every other kind of diving you do afterward, because sidemount is unforgiving of poor positioning, so it tends to fix bad habits fast.

Common Questions Before Booking

Do I need to be planning technical dives to take this course? No. Plenty of our sidemount graduates never go beyond recreational depths and simply prefer the configuration.

Is sidemount harder than back-mount? It's different rather than harder. Most divers find the first few hours require conscious thought about hose routing and trim, and then it becomes second nature.

Can I use my own cylinders? Yes, provided they're suitable for sidemount fittings. Your instructor will check your kit on day one and advise if anything needs adjusting.

How does this fit with drysuit diving? Very well. Many of our students combine sidemount with a drysuit for UK diving, and we can structure your training to cover both together if that suits your season better.

Choosing and Setting Up Your Sidemount Kit

One of the more overlooked parts of learning sidemount is working out which harness system genuinely suits the diving you plan to do. Some rigs are built primarily for cave and overhead environments, with minimal bulk and a very low profile, while others are designed with UK open water and drysuit compatibility in mind, with a bit more structure and easier donning on a boat. During the course we'll have you try a demo setup and talk through the differences based on whether you're mainly diving locally, travelling, or working toward a specific technical goal.

Cylinder choice matters too. Steel cylinders are the norm for sidemount because their negative buoyancy characteristics as they empty help keep the rig balanced, though the exact sizes and configuration you settle on will depend on your local diving and the gas volumes your dive plans call for. None of this needs to be decided before day one, but it's worth going in with an open mind rather than a fixed idea of exactly what you'll end up buying.

Why It's Worth Doing

Even if you never intend to dive a cave or push into serious decompression territory, sidemount makes you a measurably better diver. The redundancy it teaches, the discipline around gas planning, and the trim improvements all transfer directly into safer, more controlled diving in any configuration. For divers eyeing our Tec Sidemount course as the first step into the Tec Academy, it's also simply the right order to learn things in, mastering sidemount fundamentals before adding the complexity of decompression gases or overhead environments.

Spring is a good time to book. Confined water sessions let you dial in your configuration before the open water season properly gets going, so by the time the weather warms up you're diving your new setup with confidence rather than working out the kinks on a big trip. Plenty of our students also find that finishing sidemount training before summer means they arrive at any warm-water holiday diving already comfortable in the configuration, rather than trying to learn it on a precious week away.

If you're still deciding whether sidemount is the right next step versus a more traditional twin-set route into technical diving, it's worth having an honest conversation with one of our instructors about your goals. Divers heading primarily toward cave or heavily restricted wreck penetration tend to gravitate toward sidemount naturally, while those planning mostly open, deep decompression dives sometimes prefer to start with back-mounted doubles instead. Either route can lead to the same advanced qualifications eventually, so there's rarely a wrong answer, just a better fit for your specific plans.

Ready to try sidemount for yourself? Book your Tec Sidemount course or get in touch to talk through whether it's the right next step for you - we're at Bellman Court, Great Knollys Street, Reading, or call +44 (0) 118 9761 729.